All Cisco-Network Study Notes: Key Tables for CCIE Study

Key Tables for CCIE Study

Chapter 1

Table 1-2

Ethernet Cabling Types

Table 1-3

Ethernet Attack Fields

Type of Cable Pinouts Key Pins Connected

Straight-through T568A (both ends) or T568B (both ends) 1 1; 2 2; 3 3; 6 6

Cross-over T568A on one end, T568B on the added 1 3; 2 6; 3 1; 6 2

Field Description

Preamble (DIX) Provides synchronization and arresting transitions to acquiesce able clocking

of the transmitted signal. Consists of 62 alternating 1s and 0s, and ends

with a brace of 1s.

Preamble and Start

of Anatomy Delimiter

(802.3)

Same purpose and bifold bulk as DIX preamble; 802.3 artlessly renames

the 8-byte DIX conference as a 7-byte conference and a 1-byte Start of

Frame Delimiter (SFD).

Type (or Protocol

Type) (DIX)

2-byte acreage that identifies the blazon of agreement or agreement attack that

follows the header. Allows the receiver of the anatomy to apperceive how to

process a accustomed frame.

Length (802.3) Describes the length, in bytes, of the abstracts afterward the Breadth field, up

to the Ethernet trailer. Allows an Ethernet receiver to adumbrate the end of

the accustomed frame.

Destination Service

Access Point

(802.2)

DSAP; 1-byte agreement blazon field. The admeasurement limitations, forth with other

uses of the low-order bits, appropriate the afterwards accession of SNAP headers.

Source Service

Access Point

(802.2)

SSAP; 1-byte agreement blazon acreage that describes the upper-layer protocol

that created the frame.

Control (802.2) 1- or 2-byte acreage that provides mechanisms for both connectionless and

connection-oriented operation. About acclimated alone for connectionless

operation by avant-garde protocols, with a 1-byte bulk of 0x03.

CCIE Acquisition and Switching Exam Certification Guide

Table 1-3

Ethernet Attack Fields

Table 1-4

Three Types of Ethernet/MAC Address

Table 1-5

I/G and U/L Bits

Table 1-6

Ethernet Blazon Fields

Organizationally

Unique Identifier

(SNAP)

OUI; 3-byte field, about bare today, accouterment a abode for the

sender of the anatomy to cipher the OUI apery the architect of the

Ethernet NIC.

Type (SNAP) 2-byte Blazon field, application aforementioned ethics as the DIX Blazon field, overcoming

deficiencies with admeasurement and use of the DSAP field.

Type of Ethernet/MAC Abode Description and Notes

Unicast Fancy appellation for an abode that represents a single

LAN interface. The I/G bit, the best cogent bit

in the best cogent byte, is set to 0.

Broadcast An abode that agency “all accessories that abide on

this LAN appropriate now.” Consistently a bulk of hex

FFFFFFFFFFFF.

Multicast A MAC abode that implies some subset of all

devices currently on the LAN. By definition, the

I/G bit is set to 1.

Field Meaning

I/G Bifold 0 agency the abode is a unicast; Bifold 1 agency the abode is a multicast or

broadcast.

U/L Bifold 0 agency the abode is bell-ringer assigned; Bifold 1 agency the abode has been

administratively assigned, cardinal the vendor-assigned address.

Type Acreage Description

Protocol Blazon DIX V2 Blazon field; 2 bytes; registered ethics now administered by the IEEE

DSAP 802.2 LLC; 1 byte, with 2 high-order $.25 aloof for added purposes;

registered ethics now administered by the IEEE

SNAP SNAP header; 2 bytes; uses aforementioned ethics as Ethernet Agreement Type; signified

by an 802.2 DSAP of 0xAA

IP Acclamation Practice

Table 1-7

LAN About-face Forwarding Behavior

Table 1-8

Ethernet Standards

Type of

Address About-face Action

Known unicast Assiduously anatomy out the distinct interface associated with the destination

address

Unknown unicast Floods anatomy out all interfaces, except the interface on which the anatomy was

received

Broadcast Floods anatomy analogously to alien unicasts

Multicast Floods anatomy analogously to alien unicasts, unless multicast optimizations

are configured

Type of Ethernet General Description

10BASE5 Commonly alleged “thick-net”; uses coaxial cabling

10BASE2 Commonly alleged “thin-net”; uses coaxial cabling

10BASE-T Aboriginal blazon of Ethernet to use twisted-pair cabling

DIX Ethernet Adaptation 2 Band 1 and Band 2 blueprint for aboriginal Ethernet, from Digital/

Intel/ Xerox; about alleged DIX V2

IEEE 802.3 Alleged MAC due to the name of the IEEE board (Media Access

Control); aboriginal Band 1 and 2 specifications, affiliated application DIX

V2 as a basis

IEEE 802.2 Alleged LLC due to the name of the IEEE board (Logical Link

Control); Band 2 blueprint for attack accepted to assorted IEEE

LAN specifications

IEEE 802.3u IEEE accepted for Fast Ethernet (100 Mbps) over chestnut and optical

cabling; about alleged FastE

IEEE 802.3z Gigabit Ethernet over optical cabling; about alleged GigE

IEEE 802.3ab Gigabit Ethernet over chestnut cabling

CCIE Acquisition and Switching Exam Certification Guide

Table 1-9

Switch Centralized Processing

Chapter 2

Table 2-2

Private VLAN Communications Amid Ports

Table 2-3

VTP Modes and Features*

Switching

Method Description

Store-andforward

The about-face absolutely receives all $.25 in the anatomy (store) afore forwarding the frame

(forward). This allows the about-face to analysis the FCS afore forwarding the frame,

thus ensuring that errored frames are not forwarded.

Cut-through The about-face performs the abode table lookup as anon as the Destination Address

field in the attack is received. The aboriginal $.25 in the anatomy can be beatific out the

outbound anchorage afore the final $.25 in the admission anatomy are received. This does not

allow the about-face to abandon frames that abort the FCS check, but the forwarding action

is faster, consistent in lower latency.

Fragmentfree

This performs like cut-through switching, but the about-face waits for 64 bytes to be

received afore forwarding the aboriginal bytes of the approachable frame. According to

Ethernet specifications, collisions should be detected during the aboriginal 64 bytes of the

frame, so frames that are in absurdity because of a blow will not be forwarded.

Description of Who Can Talk to

Whom

Primary

VLAN Ports

Community

VLAN Ports1

Isolated

VLAN Ports1

Talk to ports in primary VLAN

(promiscuous ports)

Yes Yes Yes

Talk to ports in the aforementioned secondary

VLAN (host ports)

N/A2 Yes No

Talks to ports in addition secondary

VLAN

N/A2 No No

Function

Server

Mode

Client

Mode

Transparent

Mode

Originates VTP advertisements Yes No No

Processes accustomed advertisements to amend its VLAN

configuration

Yes Yes No

Forwards accustomed VTP advertisements Yes Yes Yes

Saves VLAN agreement in NVRAM or vlan.dat Yes No Yes

Can create, modify, or annul VLANs application configuration

commands

Yes No Yes

IP Acclamation Practice

Table 2-4

VTP Agreement Options

Table 2-5

Valid VLAN Numbers, Normal and Extended

Option Meaning

domain Sends breadth name in VTP updates. Accustomed VTP amend is abandoned if it does

not bout a switch’s breadth name. One VTP breadth name per about-face is

allowed.

password Acclimated to accomplish an MD5 assortment that is included in VTP updates. Accustomed VTP

updates are abandoned if the passwords on the sending and accepting about-face do not

match.

mode Sets server, client, or cellophane approach on the switch.

version Sets adaptation 1 or 2. Servers and audience charge bout adaptation to barter VLAN

configuration data. Cellophane approach switches at adaptation 2 advanced adaptation 1 or

version 2 VTP updates.

pruning Enables VTP pruning, which prevents broadcasts from actuality advertisement on a

per-VLAN base to switches that do not accept any ports configured as members

of that VLAN.

interface Specifies from which interface a about-face picks the antecedent MAC abode for VTP

updates.

VLAN

Number

Normal or

Extended?

Can Be Advertised and Pruned

by VTP Versions 1 and 2? Comments

0 Aloof Not accessible for use

1 Normal No On Cisco switches, the default

VLAN for all admission ports;

cannot be deleted or changed

21001 Normal Yes

10021005 Normal No Authentic accurately for use

with FDDI and TR

translational bridging

10064094 Extended No

CCIE Acquisition and Switching Exam Certification Guide

Table 2-6

VLAN Agreement and Storage

Table 2-7

Comparing ISL and 802.1Q

Function

When in VTP

Server Mode

When in VTP

Transparent Mode

Normal-range VLANs can be configured from Both VLAN

database and

configuration

modes

Both VLAN database

and configuration

modes

Extended-range VLANs can be configured from Nowhere—cannot

be configured

Configuration mode

only

VTP and normal-range VLAN configuration

commands are stored in

vlan.dat in Flash Both vlan.dat in Flash

and running

configuration1

Extended-range VLAN agreement commands

stored in

Nowhere—

extended ambit not

allowed in VTP

server mode

Running configuration

only

Feature ISL 802.1Q

VLANs accurate Normal and extended

range1

Normal and extended

range

Protocol authentic by Cisco IEEE

Encapsulates aboriginal anatomy or inserts

tag

Encapsulates Inserts tag

Supports built-in VLAN No Yes

IP Acclamation Practice

Table 2-9

Trunking Agreement Options That Lead to a Working Trunk

Configuration Command on One

Side1 Abbreviate Name Meaning

To Trunk, Other

Side Charge Be

switchport approach trunk

Trunk Consistently trunks

on this end;

sends DTP to

help added side

choose to

trunk

On, desirable, auto

switchport approach trunk

;

switchport

nonegotiate

Nonegotiate Consistently trunks

on this end;

does not send

DTP

messages

(good when

other about-face is

a non-Cisco

switch)

switchport approach activating desirable

Desirable Sends DTP

messages, and

trunks if

negotiation

succeeds

On, desirable, auto

switchport approach activating auto

Auto Replies to

DTP

messages, and

trunks if

negotiation

succeeds

On, desirable

switchport approach access

Access Never trunks;

sends DTP to

help added side

reach same

conclusion

(Never trunks)

switchport approach access

;

switchport

nonegotiate

Access (with

nonegotiate)

Never trunks;

does not send

DTP

messages

(Never trunks)

CCIE Acquisition and Switching Exam Certification Guide

Chapter 3

Table 3-2

Three Major 802.1d STP Activity Steps

Table 3-3

Default Anchorage Costs According to IEEE 802.1d

Table 3-4

IEEE 802.1d Spanning Timberline Interface States

Major Step Description

Elect the basis about-face The about-face with the everyman arch ID wins;

the accepted arch ID is 2-byte priority

followed by a MAC abode altered to that

switch.

Determine anniversary switch’s Basis Anchorage The one anchorage on anniversary about-face with the least

cost aisle aback to the root.

Determine the Designated Anchorage for anniversary articulation Back assorted switches affix to the same

segment, this is the about-face that assiduously the

least bulk Hello assimilate a segment.

Speed of Ethernet Aboriginal IEEE Bulk Revised IEEE Cost

10 Mbps 100 100

100 Mbps 10 19

1 Gbps 1 4

10 Gbps 1 2

State

Forwards

Data Frames?

Learn Antecedent MACs of

Received Frames?

Transitory or Stable

State?

Blocking No No Stable

Listening No No Transitory

Learning No Yes Transitory

Forwarding Yes Yes Stable

Disabled No No Stable

IP Acclamation Practice

Table 3-5

PortFast, UplinkFast, and BackboneFast

Table 3-7

PAgP and LACP Agreement Settings and Recommendations

Table 3-8

RSTP Articulation Types

Feature Requirements for Use How Convergence Is Optimized

PortFast Acclimated on admission ports that are not

connected to added switches or hubs

Immediately puts the anchorage into

forwarding accompaniment already the anchorage is

physically working

UplinkFast Acclimated on admission band switches that

have assorted uplinks to

distribution/core switches

Immediately replaces a absent RP with an

alternate RP, anon assiduously on

the RP, and triggers updates of all

switches’ CAMs

BackboneFast Acclimated to ascertain aberrant articulation failures,

typically in the arrangement core

Avoids cat-and-mouse for Maxage to expire

when its RP ceases to accept Hellos;

does so by querying the about-face attached

to its RP

PAgP Ambience LACP 802.1AD Ambience Action

on on

Disables PAgP or LACP, and armament the

port into the PortChannel

off off

Disables PAgP or LACP, and prevents the

port from actuality allotment of a PortChannel

auto passive

Uses PAgP or LACP, but waits on other

side to accelerate aboriginal PAgP or LACP message

desirable active

Uses PAgP or LACP, and initiates the

negotiation

Link Blazon Description

Point-to-point Connects a about-face to one added switch; Cisco switches amusement FDX links in which

Hellos are accustomed as point-to-point links.

Shared Connects a about-face to a hub; the important agency is that switches are attainable off

that port.

Edge Connects a about-face to a distinct end-user device.

CCIE Acquisition and Switching Exam Certification Guide

Table 3-9

RSTP and STP Anchorage States

Table 3-10

RSTP and STP Anchorage Roles

Table 3-11

Protocols and Standards for Chapter 3

Table 3-12

IEEE 802.1d STP Timers

Administrative Accompaniment STP Accompaniment (802.1d) RSTP Accompaniment (802.1w)

Disabled Disabled Discarding

Enabled Blocking Discarding

Enabled Alert Discarding

Enabled Acquirements Learning

Enabled Forwarding Forwarding

RSTP Role Definition

Root Anchorage Aforementioned as 802.1d Basis Port.

Designated Anchorage Aforementioned as 802.1d Designated Port.

Alternate Anchorage Aforementioned as the Alternating Anchorage abstraction in UplinkFast; an alternating Basis Port.

Backup Anchorage A anchorage that is absorbed to the aforementioned link-type aggregate articulation as addition anchorage on

the aforementioned switch, but the added anchorage is the DP for that segment. The Backup

Port is accessible to booty over if the DP fails.

Name Standards Body

RSTP IEEE 802.1w

MST IEEE 802.1s

STP IEEE 802.1d

LACP IEEE 802.1AD

Dot1Q trunking IEEE 802.1Q

PVST+ Cisco

RPVST+ Cisco

PagP Cisco

Timer Absence Purpose

Hello 2 sec Breach at which the basis sends Hellos

Forward

Delay

15 sec Time that about-face leaves a anchorage in alert accompaniment and acquirements state;

also acclimated as the abbreviate CAM abeyance timer

Maxage 20 sec Time afterwards audition a Hello afore assertive that the basis has

failed

IP Acclamation Practice

Chapter 4

Table 4-2

Classful Arrangement Review

Table 4-12

RFC 1918 Clandestine Abode Space

Table 4-13

NAT Terminology

Class of

Address

Size of Network

and Host Parts of

the Addresses

Range of

First Octet

Values

Default Mask

for Anniversary Class

of Network

Identifying Bits

at Beginning of

Address

A 8/24 1–126 255.0.0.0 0

B 16/16 128–191 255.255.0.0 10

C 24/8 192–223 255.255.255.0 110

D — 224–239 — 1110

E — 240–255 — 1111

Range of IP Addresses Class of Networks Cardinal of Networks

10.0.0.0 to 10.255.255.255 A 1

172.16.0.0 to 172.31.255.255 B 16

192.168.0.0 to

192.168.255.255

C 256

Name

Location of Host

Represented by Address

IP Abode Space in Which

Address Exists

Inside Bounded abode Central the activity arrangement Allotment of the activity IP address

space; about a clandestine IP

address

Inside Global abode Central the activity arrangement Allotment of the accessible IP abode space

Outside Bounded abode In the accessible Internet; or,

outside the enterprise

network

Part of the activity IP address

space; about a clandestine IP

address

Outside Global abode In the accessible Internet; or,

outside the enterprise

network

Part of the accessible IP abode space

CCIE Acquisition and Switching Exam Certification Guide

Table 4-14

Variations on NAT

Table 4-15

Protocols and Standards for Chapter 4

Name Function

Static NAT Statically correlates the aforementioned accessible IP abode for use by

the aforementioned bounded host every time. Does not conserve IP

addresses.

Dynamic NAT Pools the accessible accessible IP addresses, aggregate amid a

group of bounded hosts, but with alone one bounded host at a time

using a accessible IP address. Does not conserve IP addresses.

Dynamic NAT with afflict (PAT) Like activating NAT, but assorted bounded hosts allotment a single

public IP abode by multiplexing application TCP and UDP

port numbers. Conserves IP addresses.

NAT for overlapping abode Can be done with any of the aboriginal three types. Translates

both antecedent and destination addresses, instead of aloof the

source (for packets activity from activity to the Internet).

Name Affiliated In

IP RFC 791

Subnetting RFC 950

NAT RFC 1631

Private acclamation RFC 1918

CIDR RFCs 1517–1520

IP Acclamation Practice

Table 4-17

IP Attack Fields

Field Meaning

Version Adaptation of the IP protocol. Best networks use IPv4 today, with IPv6

becoming added popular. The attack architecture reflects IPv4.

Header Breadth Defines the breadth of the IP header, including addition fields. Because the

length of the IP attack charge consistently be a assorted of 4, the IP attack length

(IHL) is assorted by 4 to accord the absolute cardinal of bytes.

DS Acreage Differentiated Services Field. This byte was originally alleged the Blazon of

Service (ToS) byte, but was redefined by RFC 2474 as the DS Field. It is

used for appearance packets for the purpose of applying altered affection of

service (QoS) levels to altered packets.

Packet Breadth Identifies the absolute breadth of the IP packet, including the data.

Identification Acclimated by the IP packet breach process. If a distinct packet is

fragmented into assorted packets, all $.25 of the aboriginal packet

contain the aforementioned identifier, so that the aboriginal packet can be reassembled.

Flags 3 $.25 acclimated by the IP packet breach process.

Fragment Offset A cardinal set in a fragment of a above packet that identifies the fragment’s

location in the above aboriginal packet.

Time to Live (TTL) A bulk acclimated to anticipate acquisition loops. Routers cutback this acreage by 1

each time the packet is forwarded; already it decrements to 0, the packet is

discarded.

Protocol A acreage that identifies the capacity of the abstracts allocation of the IP packet. For

example, agreement 6 implies a TCP attack is the aboriginal affair in the IP packet

data field.

Header Checksum A bulk acclimated to abundance a anatomy analysis arrangement (FCS) value, whose purpose

is to actuate if any bit errors occurred in the IP attack (not the data)

during transmission.

Source IP Abode The 32-bit IP abode of the sender of the packet.

Destination IP

Address

The 32-bit IP abode of the advised almsman of the packet.

Optional Header

Fields and Padding

IP supports added attack fields for approaching amplification via optional

headers. Also, if these addition headers do not use a assorted of 4 bytes,

padding bytes are added, comprised of all bifold 0s, so that the attack is a

multiple of 4 bytes in length.

CCIE Acquisition and Switching Exam Certification Guide

Table 4-18

IP Agreement Acreage Values

Chapter 5

Table 5-2

Comparing RARP, BOOTP, and DHCP

Table 5-3

SNMP Adaptation Summaries

Protocol Name Agreement Number

ICMP 1

TCP 6

UDP 17

EIGRP 88

OSPF 89

PIM 103

Feature RARP BOOTP DHCP

Relies on server to admeasure IP addresses Yes Yes Yes

Encapsulates letters central IP and UDP, so they can be

forwarded to a alien server

No Yes Yes

Client can ascertain its own mask, gateway, DNS, and download

server

No Yes Yes

Dynamic abode appointment from a basin of IP addresses,

without acute adeptness of applicant MACs

No No Yes

Allows acting charter of IP abode No No Yes

Includes extensions for registering client’s FQDN with a DNS No No Yes

SNMP

Version Description

1 Uses SMIv1, simple affidavit with communities, but acclimated MIB-I originally.

2 Uses SMIv2, removed claim for communities, added GetBulk and Inform

messages, but began with MIB-II originally.

2c Pseudo-release (RFC 1905) that accustomed SNMPv1-style communities with SNMPv2;

otherwise agnate to SNMPv2.

3 Mostly identical to SNMPv2, but adds decidedly bigger security, although it

supports communities for astern compatibility. Uses MIB-II.

IP Acclamation Practice

Table 5-4

SNMP Agreement Letters (RFCs 1157 and 1905)

Message

Initial

Version

Response

Message

Typically

Sent By Main Purpose

Get 1 Acknowledgment Administrator A appeal for a single

variable’s value.

GetNext 1 Acknowledgment Administrator A appeal for the next

single MIB blade variable

in the MIB tree.

GetBulk 2 Acknowledgment Administrator A appeal for multiple

consecutive MIB

variables with one

request. Useful for

getting complex

structures, for example,

an IP acquisition table.

Response 1 None Abettor Acclimated to acknowledge with

the advice in Get

and Set requests.

Set 1 Acknowledgment Administrator Beatific by a administrator to an

agent to acquaint the abettor to

set a capricious to a

particular value. The

agent replies with a

Response message.

Trap 1 None Abettor Allows agents to send

unsolicited information

to an SNMP manager.

The administrator does not

reply with any SNMP

message.

Inform 2 Acknowledgment Administrator A bulletin used

between SNMP

managers to acquiesce MIB

data to be exchanged.

CCIE Acquisition and Switching Exam Certification Guide

Table 5-5

Protocols and Standards for Chapter 5

Chapter 6

Table 6-2 Matching Argumentation and Load-Balancing Options for Anniversary Switching Path

Name Affiliated In

ARP RFC 826

Proxy ARP RFC 1027

RARP RFC 903

BOOTP RFC 951

DHCP RFC 2131

DHCP FQDN advantage Internet-Draft

HSRP Cisco proprietary

VRRP RFC 3768

GLBP Cisco proprietary

CDP Cisco proprietary

NTP RFC 1305

Syslog RFC 3164

SNMP Adaptation 1 RFCs 1155, 1156, 1212, 1157, 1213, 1215

SNMP Adaptation 2 RFCs 1902–1907, 3416

SNMP Adaptation 2c RFC 1901

SNMP Adaptation 3 RFCs 2578–2580, 3410–3415

Good Starting Point: RFC 3410

Switching Path

Tables that Authority the Forwarding

Information Load-Balancing Method

Process switching Acquisition table Per packet

Fast switching Fast-switching accumulation (per breeze route

cache)

Per destination IP address

CEF FIB and adjacency tables Per a assortment of the packet antecedent and

destination, or per packet

IP Acclamation Practice 18

Table 6-3 Facts and Behavior Related to InARP

1Point-to-point interfaces avoid InARP letters because of their “send all packets for addresses in this subnet using

the alone DLCI on the subinterface” logic.

Table 6-5 MLS Band 3 Interfaces

Fact/Behavior Point-to-Point Multipoint or Physical

Does InARP crave LMI? Consistently Always

Is InARP enabled by default? Yes Yes

Can InARP be disabled? No Yes

Ignores accustomed InARP messages? Always1 Back InARP is disabled

Interface

Forwarding to

Adjacent Device

Configuration

Requirements

VLAN interface Uses Band 2 argumentation and L2 MAC

address table

Create VLAN interface;

VLAN charge additionally exist

Physical (routed) interface Assiduously out concrete interface Use no switchport command

to actualize a baffled interface

PortChannel (switched)

interface

Not applicable; aloof acclimated as

another Band 2 forwarding path

No appropriate configuration;

useful in affiliation with

VLAN interfaces

PortChannel (routed)

interface

Balances above links in

PortChannel

Needs no switchport

command in adjustment to be used

as a baffled interface;

optionally change loadbalancing

method

19 CCIE Acquisition and Switching Exam Certification Guide

Table 6-6 Action Acquisition Instructions (set Commands)

Table 6-7 Protocols and Standards for Chapter 6

Command Comments

set ip next-hop ip-address [...ip-address] Next-hop addresses charge be in a connected

subnet; assiduously to the aboriginal abode in the list

for which the associated interface is up.

set ip absence next-hop ip-address [...ip-address] Aforementioned argumentation as antecedent command, except

policy acquisition aboriginal attempts to avenue based on

the acquisition table.

set interface interface-type interface-number

[...interface-type interface-number]

Forwards packets application the aboriginal interface in

the account that is up.

set absence interface interface-type interfacenumber

[...interface-type interface-number]

Same argumentation as antecedent command, except

policy acquisition aboriginal attempts to avenue based on

the acquisition table.

set ip antecedence cardinal | name Sets IP antecedence bits; can be decimal value

or ASCII name.

set ip tos [number] Next-hop addresses charge be in a connected

subnet; assiduously to the aboriginal abode in the list

for which the associated interface is up.

Name Affiliated In

Address Resolution Agreement (ARP) RFC 826

Reverse Abode Resolution Agreement (RARP) RFC 903

Frame Relay Inverse ARP (InARP) RFC 2390

Frame Relay Multiprotocol Encapsulation RFC 2427

Differentiated Services Cipher Point (DSCP) RFC 2474

IP Acclamation Practice 20

Chapter 7

Table 7-2 RIP Feature Summary

*RIPv2-only features

Function Description

Transport UDP, anchorage 520.

Metric Hop count, with 15 as the best accessible metric, and 16

considered to be infinite.

Hello breach None; RIP relies on the approved abounding acquisition updates

instead.

Update destination Bounded subnet advertisement (255.255.255.255) for RIPv1;

224.0.0.9 multicast for RIPv2.

Update breach 30 seconds.

Full or fractional updates Abounding updates anniversary interval. For on-demand circuits, allows

RIP to accelerate abounding updates once, and again abide bashful until

changes occur, per RFC 2091. Abounding updates anniversary interval.

Triggered updates Yes, back routes change.

Multiple routes to the aforementioned subnet Allows installing 1 to 6 (default 4) equal-metric routes to

the aforementioned subnet in a distinct acquisition table.

Authentication* Allows both plain-text and MD5 authentication.

Subnet affectation in updates* RIPv2 transmits the subnet affectation with anniversary route, thereby

supporting VLSM, authoritative RIPv2 classless. This feature

also allows RIPv2 to abutment discontiguous networks.

VLSM* Accurate as a aftereffect of the admittance of subnet masks in

the acquisition updates.

Route Tags* Allows RIP to tag routes as they are redistributed into RIP.

Next-Hop field* Supports the appointment of a next-hop IP abode for a

route, acceptance a router to acquaint a next-hop router that

is altered from itself.

21 CCIE Acquisition and Switching Exam Certification Guide

Table 7-3 RIP Features Related to Convergence and Loop Prevention

Table 7-4 RIP Per-Interface Actions, and How to Disable Them Already Enabled

Function Description

Split border Instead of announcement all routes out a accurate interface, RIP omits the routes

whose approachable interface acreage matches the interface out which the amend would

be sent.

Triggered

update

The actual sending of a new amend back acquisition advice changes,

instead of cat-and-mouse for the Amend timer to expire.

Route

poisoning

The activity of sending an infinite-metric (hop calculation 16) avenue in acquisition updates

when that avenue fails.

Poison about-face The act of announcement a berserk avenue (metric 16) out an interface, but in

reaction to accepting that aforementioned berserk avenue in an amend accustomed on that same

interface.

Update timer The timer that specifies the time breach over which updates are sent. Each

interface uses an absolute timer, behind to 30 seconds.

Holddown

timer

A per-route timer (default 180 seconds) that begins back a route’s metric

changes to a above value. The router does not add an addition avenue for this

subnet to its acquisition table until the Holddown timer for that avenue expires.

Invalid timer A per-route timer that increases until it receives a acquisition amend that confirms

the avenue is still valid, aloft which the timer is displace to 0. If the updates cease, the

Invalid timer will abound until it alcove the timer ambience (default 180 seconds),

after which the avenue is advised invalid.

Flush

(Garbage)

timer

A per-route timer that is displace and grows with the Invalid timer. Back the Flush

timer mark is accomplished (default 240 seconds), the router removes the avenue from

the acquisition table and accepts new routes to the bootless subnet.

RIP Function How to Disable

Sending RIP updates Make the interface passive: configure router rip, followed by passiveinterface

type number

Listening for RIP updates Clarify all admission routes application a administer list

Advertising the

connected subnet

Filter outbound advertisements on added interfaces application distribute

lists, clarification an interface’s affiliated subnet

IP Acclamation Practice 22

Table 7-5 Protocols and Standards for Chapter 7

Chapter 8

Table 8-2 EIGRP Feature Summary

Protocol or Feature Standard

RIP (Version 1) RFC 1058

RIP (Version 2) RFC 2453

RIP Amend Affidavit RFC 2082

RIP Triggered Extensions for On-Demand Circuits RFC 2091

Feature Description

Transport IP, agreement blazon 88 (does not use UDP or TCP).

Metric Based on accountable bandwidth and accumulative adjournment by default,

and optionally load, reliability, and MTU.

Hello breach Breach at which a router sends EIGRP Hello letters on an

interface.

Hold timer Timer acclimated to actuate back a adjoining router has failed,

based on a router not accepting any EIGRP messages, including

Hellos, in this timer period.

Update destination abode Normally beatific to 224.0.0.9, with retransmissions actuality beatific to each

neighbor’s unicast IP address.

Full or fractional updates Abounding updates are acclimated back new neighbors are discovered;

otherwise, fractional updates are used.

Authentication Supports MD5 affidavit only.

23 CCIE Acquisition and Switching Exam Certification Guide

Table 8-2 EIGRP Feature Summary

Table 8-3 EIGRP Features Related to Convergence

Feature Description

VLSM/classless EIGRP includes the affectation with anniversary route, additionally acceptance it to

support discontiguous networks and VLSM.

Route Tags Allows EIGRP to tag routes as they are redistributed into EIGRP.

Next-hop acreage Supports the advertisement of routes with a altered next-hop

router than the announcement router.

Manual avenue summarization Allows avenue summarization at any point in the EIGRP network.

Multiprotocol Supports the advertisement of IPX and AppleTalk routes.

EIGRP Convergence

Function Description

Reported ambit (RD) The metric (distance) of a avenue as appear by a adjoining router

Feasible ambit (FD) The metric bulk for the lowest-metric aisle to adeptness a accurate subnet

Feasibility activity Back assorted routes to adeptness one subnet exist, the case in which one

route’s RD is lower than the FD

Successor avenue The avenue to anniversary destination prefix for which the metric is the lowest

metric

Feasible almsman (FS) A avenue that is not a almsman avenue but meets the achievability condition;

can be acclimated back the almsman avenue fails, afterwards causing loops

Input accident Any accident that could change a router’s EIGRP cartography table

Local ciphering An EIGRP router’s acknowledgment to an ascribe event, arch to the use of a

feasible almsman or activity alive on a route

IP Acclamation Practice 24

Table 8-4 EIGRP Features Related to Convergence

Table 8-5 EIGRP Avenue Load-Balancing Commands

Table 8-7 EIGRP Bulletin Summary

Option This Router Is Accustomed To

connected Acquaint affiliated routes, but alone for interfaces akin with a network

command.

summary Acquaint autosummarized or statically configured arbitrary routes.

static Acquaint changeless routes, bold the redistribute changeless command is configured.

redistributed Acquaint redistributed routes, bold redistribution is configured.

receive-only Not acquaint any routes. This advantage cannot be acclimated with any added option.

Router EIGRP

Subcommand Meaning

variance Any FS avenue whose metric is beneath than the about-face bulk multiplied

by the FD is added to the acquisition table (within the restrictions of the

maximum-paths command).

maximum-paths {1..16} The best cardinal of routes to the aforementioned destination accustomed in the

routing table. Defaults to 4.

traffic-share counterbalanced The router balances above the routes, giving added packets to lowermetric

routes.

no traffic-share

balanced

The router balances above the routes equally, behindhand of metrics.

traffic-share min

across-interfaces

Although assorted routes are installed, sends cartage application alone the

lowest-metric routes.

EIGRP

Packet Purpose

Hello Identifies neighbors, exchanges parameters, and is beatific periodically as a keepalive

function

Update Informs neighbors about acquisition information

Ack Acknowledges Update, Query, and Acknowledgment packets

Query Asks adjoining routers to verify their avenue to a accurate subnet

Reply Beatific by neighbors to acknowledgment to a Query

Goodbye Acclimated by a router to acquaint its neighbors back the router is alluringly shutting down

25 CCIE Acquisition and Switching Exam Certification Guide

Chapter 9

Table 9-2 OSPF Messages

Table 9-3 OSPF Arrangement Types

1 Absence on Anatomy Relay point-to-point subinterfaces.

2 Absence on Anatomy Relay concrete and multipoint subinterfaces.

Message Description

Hello Acclimated to ascertain neighbors, accompany a acquaintance accord to a 2-way

state, and adviser a neighbor’s admiration in case it fails

Database Description

(DD or DBD)

Used to barter abrupt versions of anniversary LSA, about on initial

topology exchange, so that a router knows a account of that neighbor’s LSAs

Link-State Request

(LSR)

A packet that identifies one or added LSAs about which the sending

router would like the acquaintance to accumulation abounding capacity about the LSAs

Link-State Update

(LSU)

A packet that contains absolutely abundant LSAs, about beatific in acknowledgment to

an LSR message

Link-State

Acknowledgement

(LSAck)

Sent to affirm cancellation of an LSU message

Interface Type

Uses DR/

BDR?

Default

Hello

Interval

Requires a

neighbor

Command?

More than Two

Hosts Allowed

in the Subnet?

Broadcast Yes 10 No Yes

Point-to-point1 No 10 No No

Nonbroadcast2 (NBMA) Yes 30 Yes Yes

Point-to-multipoint No 30 No Yes

Point-to-multipoint nonbroadcast No 30 Yes Yes

Loopback No — — No

IP Acclamation Practice 26

Table 9-4 OSPF LSA Types

Table 9-5 OSPF Chubby Breadth Types

LSA

Type Accepted Name Description

1 Router One per router, advertisement RID and all interface IP

addresses. Represents butt networks as well.

2 Arrangement One per alteration network. Created by the DR on the

subnet, and represents the subnet and the router

interfaces affiliated to the subnet.

3 Net Arbitrary Created by ABRs to represent one area’s blazon 1

and 2 LSAs back actuality advertised into another

area. Defines the links (subnets) in the agent area,

and cost, but no cartography data.

4 ASBR Arbitrary Like a blazon 3 LSA, except it advertises a host

route acclimated to adeptness an ASBR.

5 AS Alien Created by ASBRs for alien routes injected

into OSPF.

6 Group Membership Authentic for MOSPF; not accurate by Cisco IOS.

7 NSSA Alien Created by ASBRs central an NSSA area, instead

of a blazon 5 LSA.

8 Alien Attributes Not implemented in Cisco routers.

9–11 Opaque Acclimated as all-encompassing LSAs to acquiesce for accessible future

extension of OSPF; for example, blazon 10 has been

adapted for MPLS cartage engineering.

Area Type

Stops Bang of

Type 5 LSAs?

Stops Bang of

Type 3 LSAs?

Allows Creation of

Type 7 LSAs Inside

the Area?

Stub Yes No No

Totally chubby Yes Yes No

Not-so-stubby area

(NSSA)

Yes No Yes

Totally NSSA Yes Yes Yes

27 CCIE Acquisition and Switching Exam Certification Guide

Table 9-6 Butt Breadth Agreement Options

Table 9-7 OSPF Affidavit Types

Table 9-8 Effect of the breadth affidavit Command on OSPF Interface Affidavit Settings

Stub Blazon Router OSPF Subcommand

NSSA breadth area-id nssa

Totally NSSA breadth area-id nssa no-summary

Stub breadth area-id stub

Totally chubby breadth area-id butt no-summary

Type Meaning

Enabling Interface

Subcommand

Authentication Key Configuration

Interface Subcommand

0 None ip ospf affidavit absent —

1 Clear argument ip ospf affidavit ip ospf authentication-key key-value

2 MD5 ip ospf authentication

message-digest

ip ospf message-digest-key key-number

md5 key-value

area affidavit COMMAND Interfaces in That Breadth Absence to Use...

Blazon 0

area num affidavit Blazon 1

area num affidavit message-digest Blazon 2

IP Acclamation Practice 28

Table 9-9 Configuring OSPF Affidavit on Virtual Links

Table 9-10 Protocols and Corresponding Standards for Chapter 9

Type Command Syntax for Virtual Links

0 breadth num virtual-link router-id affidavit null

1 breadth num virtual-link router-id affidavit authentication-key key-value

2 breadth num virtual-link router-id affidavit message-digest message-digest-key

key-num md5 key-value

Name Standard

OSPF Adaptation 2 RFC 2328

The OSPF Opaque LSA Advantage RFC 2370

The OSPF Not-So-Stubby Breadth (NSSA) Advantage RFC 3101

OSPF Butt Router Advertisement RFC 3137

Traffic Engineering (TE) Extensions to OSPF Adaptation 2 RFC 3630

Graceful OSPF Restart RFC 3623

29 CCIE Acquisition and Switching Exam Certification Guide

Table 9-12 OSPF Timer Summary

Timer Meaning

Maxage The best time an LSA can be in a router’s LSDB, afterwards accepting a

newer archetype of the LSA, afore the LSA is removed. Absence is 3600 seconds.

LSRefresh The timer breach per LSA on which a router refloods an identical LSA, except

for a 1-larger arrangement number, to anticipate the cessation of Maxage. Absence is

1800 seconds.

Hello Per interface; time breach amid Hellos. Absence is 10 or 30 seconds,

depending on interface type.

Dead Per interface; time breach in which a Hello should be accustomed from a neighbor.

If not received, the acquaintance is advised to accept failed. Absence is four times

Hello.

Wait Per interface; set to the aforementioned cardinal as the asleep interval. Defines the time a

router will delay to get a Hello asserting a DR afterwards extensive a 2WAY accompaniment with

that neighbor.

Retransmission Per interface; the time amid sending an LSU, not accepting an

acknowledgement, and again resending the LSU. Absence is 5 seconds.

Inactivity Countdown timer, per neighbor, acclimated to ascertain back a acquaintance has not been

heard from for a complete asleep interval. It starts according to the asleep interval,

counts down, and is displace to be according to the asleep breach back anniversary Hello is

received.

Poll Breach On NBMA networks, the aeon at which Hellos are beatific to a acquaintance back the

neighbor is down. Absence is 60 seconds.

Flood (Pacing) Per interface; defines the breach amid alternating LSUs back flooding

LSAs. Absence is 33 ms.

Retransmission

(Pacing)

Per interface; defines the breach amid retransmitted packets as allotment of a

single retransmission event. Absence is 66 ms.

Lsa-group

(Pacing)

Per OSPF process. LSA’s LSRefresh intervals time out independently. This timer

improves LSU reflooding adeptness by waiting, accession several LSAs whose

LSRefresh timers expire, and calamity all these LSAs together. Absence is

240 seconds.

IP Acclamation Practice 30

Table 9-13 OSPF Acquaintance States

Table 9-14 OSPF Numeric Ranges

State Meaning

Down No Hellos accept been accustomed from this acquaintance for added than the asleep interval.

Attempt This router is sending Hellos to a manually configured neighbor.

Init A Hello has been accustomed from the neighbor, but it did not accept the router’s RID in it.

This is a abiding accompaniment back Hello ambit do not match.

2WAY A Hello has been accustomed from the neighbor, and it has the router’s RID in it. This is

a abiding accompaniment for pairs of DROther neighbors.

ExStart Currently negotiating the DD arrangement numbers and master/slave argumentation acclimated for DD

packets.

Exchange Finished negotiating, and currently exchanging DD packets.

Loading All DD packets exchanged, and currently affairs the complete LSDB entries with

LSU packets.

Full Neighbors are adjoining (fully adjacent), and should accept identical LSDB entries for

the breadth in which the articulation resides. Acquisition table calculations begin.

Setting Ambit of Values

Single interface bulk 1 to 65,535 (216 – 1)

Complete avenue bulk 1 to 16,777,215 (224 – 1)

Infinite avenue bulk 16,777,215 (224 – 1)

Reference bandwidth (units: Mbps) 1 to 4,294,967

OSPF PID 1 to 65,535 (216 – 1)

31 CCIE Acquisition and Switching Exam Certification Guide

Chapter 10

Table 10-6 Administrative Distances

Table 10-7 Absence Metrics and Avenue Metric Types in IGP Avenue Redistribution

Route Blazon Administrative Distance

Connected 0

Static 1

EIGRP arbitrary avenue 5

EBGP 20

EIGRP (internal) 90

IGRP 100

OSPF 110

IS-IS 115

RIP 120

EIGRP (external) 170

iBGP 200

Unreachable 255

IGP into Which Routes Are

Redistributed

Default

Metric Absence (and Possible) Metric Types

RIP None RIP has no abstraction of alien routes

EIGRP None External

OSPF 20/1* E2 (E1 or E2)

IS-IS 0 L1 (L1, L2, L1/L2, or external)

IP Acclamation Practice 32

Table 10-8 IGP Adjustment of Antecedence for Choosing Routes Afore Considering the Metric

Table 10-9 OSPF Avenue Summarization Commands

Table 10-10 Four Methods for Acquirements Absence Routes

IGP Adjustment of Antecedence of Metric

RIP No added considerations

EIGRP Internal, again external

OSPF Intra-area, inter-area, E1, again E2*

IS-IS L1, L2, external

Where acclimated Command

ASBR summary-address {{ip-address mask} | {prefix mask}} [not-advertise]

[tag tag]

ABR breadth area-id ambit ip-address affectation [advertise | not-advertise] [cost cost]

Feature RIP EIGRP OSPF

Static avenue to 0.0.0.0, with the redistribute changeless command Yes Yes No

The default-information arise command Yes No Yes

The ip default-network command Yes Yes No

Using arbitrary routes No Yes No

33 CCIE Acquisition and Switching Exam Certification Guide

Chapter 11

Table 11-2 BGP Acquaintance Arbitrary Table

BGP Feature Description and Values

TCP anchorage 179

Setting the keepalive breach and authority time

(using the bgp timers keepalive holdtime

router subcommand or acquaintance timers

command, per neighbor)

Default to 60 and 180 seconds; ascertain time

between keepalives and time for which silence

means the acquaintance has failed

What makes a acquaintance centralized BGP

(iBGP)?

Neighbor is in the aforementioned AS

What makes a acquaintance alien BGP

(eBGP)?

Neighbor is in addition AS

How is the BGP router ID (RID) determined? In order:

The bgp router-id command

The accomplished IP of an up/up loopback at the time

that the BGP activity starts

The accomplished IP of addition up/up interface at the

time that the BGP activity starts.

How is the antecedent IP abode acclimated to adeptness a

neighbor determined?

Defined with the acquaintance update-source

command; or, by default, uses the outgoing

interface IP abode for the avenue acclimated to adeptness the

neighbor

How is the destination IP abode acclimated to

reach a acquaintance determined?

Explicitly authentic on the acquaintance command

Auto-summary* Off by default, enabled with auto-summary

router subcommand

Neighbor affidavit MD5 only, application the acquaintance password

command

IP Acclamation Practice 34

Table 11-3 BGP Acquaintance States

Table 11-4 BGP Bulletin Types

Table 11-5 Key Features of the BGP arrangement Command

State

Listen for

TCP?

Initiate

TCP?

TCP

Up?

Open

Sent?

Open

Received?

Neighbor

Up?

Idle No

Connect Yes

Active Yes Yes

Open beatific Yes Yes Yes Yes

Open

confirm

Yes Yes Yes Yes Yes

Established Yes Yes Yes Yes Yes Yes

Message Purpose

Open Acclimated to authorize a acquaintance accord and barter basal parameters.

Keepalive Acclimated to advance the acquaintance relationship, with nonreceipt of a keepalive

message aural the adjourned Authority timer causing BGP to accompany bottomward the

neighbor connection. (The timers can be configured with the bgp timers

keepalive holdtime subcommand or the acquaintance [ip-address | peer-group-name]

timers keepalive holdtime BGP subcommand.)

Update Acclimated to barter acquisition information, as covered added absolutely in the abutting section.

Notification Acclimated back BGP errors occur; causes a displace to the acquaintance accord when

sent.

Feature Implication

No affectation is configured Assumes the absence classful mask.

Matching argumentation with no auto-summary

configured

An IP avenue charge bout both the prefix and prefix

length (mask).

Matching argumentation with auto-summary

configured

If the arrangement command lists a classful network, it

matches if any subnets of the classful arrangement exist.

NEXT_HOP of BGP avenue added to the

BGP table*

Uses abutting hop of IP route.

Maximum cardinal injected by the

network command into one BGP process

200

Purpose of the route-map advantage on the

network command

Can be acclimated to clarify routes and dispense PAs,

including NEXT_HOP*.

35 CCIE Acquisition and Switching Exam Certification Guide

Table 11-6 Summary: Injecting Arbitrary Routes in BGP

Table 11-7 BGP ORIGIN Codes

Table 11-8 Arbitrary of Rules Regarding Which Routes BGP Does Not Include in an Update

Table 11-9 Conditions for Changing the NEXT_HOP PA

Command

Component

Subnets Removed Routes It Can Summarize

auto-summary (with

redistribution)

All Alone those injected into BGP on that router

using the redistribute command

aggregate-address All, none, or a subset Any prefixes already in the BGP table

auto-summary (with the

network command)

None Alone those injected into BGP on that router

using the arrangement command

ORIGIN Code

Cisco IOS

Notation

Used for Routes Injected Due to the Following

Commands

IGP i network, aggregate-address (in some cases), and neighbor

default-originate commands

EGP e Exterior Aperture Agreement (EGP). No specific commands

apply.

Incomplete ? redistribute, aggregate-address (in some cases), and

default- advice arise command

iBGP and/or eBGP Routes Not Taken from the BGP Table

Both Routes that are not advised “best”

Both Routes akin by a abjure article in an outbound BGP filter

iBGP iBGP-learned routes*

eBGP Routes whose AS_PATH includes the ASN of the eBGP associate to

which a BGP Amend will be sent

Type of

Neighbor

Default Activity for Advertised

Routes

Command to About-face to Other

Behavior

iBGP Do not change the NEXT_HOP neighbor… next-hop-self

eBGP Change the NEXT_HOP to the update

source IP address

neighbor… next-hop- unchanged

IP Acclamation Practice 36

Table 11-10 BGP Subcommands Acclimated for Confederations

Table 11-11 Types of Neighbors to Which Prefixes Are Reflecte

Table 11-13 BGP PAs

Purpose Command

Define a router’s sub-AS router bgp sub-as

Define the accurate AS bgp amalgamation identifier asn

To analyze a adjoining AS as addition sub-AS bgp amalgamation aeon sub-asn

Location from Which a

Prefix Is Learned

Are Routes Advertised to

Clients?

Are Routes Advertised to

Non-clients?

Client Yes Yes

Non-client Yes No

eBGP Yes Yes

Path Attribute Description Characteristics

AS_PATH Lists ASNs through which the avenue has

been advertised

Well accepted Mandatory

NEXT_HOP Lists the next-hop IP abode acclimated to

reach an NLRI

Well accepted Mandatory

AGGREGATOR Lists the RID and ASN of the router that

created a arbitrary NLRI

Optional Transitive

ATOMIC_AGGREGA TE Tags a arbitrary NLRI as actuality a

summary

Well known

Discretionary

ORIGIN Bulk implying from area the route

was taken for bang into BGP; i(IGP),

e (EGP), or ? (incomplete information)

Well accepted Mandatory

ORIGINATOR_ID Acclimated by RRs to denote the RID of the

iBGP acquaintance that injected the NLRI

into the AS

Optional

Nontransitive

CLUSTER_LIST Acclimated by RRs to account the RR array IDs in

order to anticipate loops

Optional

Nontransitive

37 CCIE Acquisition and Switching Exam Certification Guide

Table 11-14 Summary: Methods to Introduce Entries into the BGP Table

Chapter 12

Table 12-2 IP Antecedence Ethics and Names

Method Arbitrary Description

network command Advertises a avenue into BGP. Depends on the actuality of the

configured network/subnet in the IP acquisition table.

Redistribution Takes IGP, static, or affiliated routes; metric (MED)

assignment is not required.

Manual summarization Requires at atomic one basic subnet in the BGP table;

options for befitting all basic subnets, suppressing all

from advertisement, or suppressing a subset from being

advertised.

default-information arise Requires a absence avenue in the IP acquisition table, additional the

redistribute command.

neighbor default- arise With the addition avenue map, requires the avenue map to match

the IP acquisition table with a admittance activity afore announcement a

default route. Afterwards the avenue map, the absence is always

advertised.

Name Decimal Bulk Bifold Value

Routine Antecedence 0 000

Priority Antecedence 1 001

Immediate Antecedence 2 010

Flash Antecedence 3 011

Flash Override Antecedence 4 100

Critic/Critical Antecedence 5 101

Internetwork Control Antecedence 6 110

Network Control Antecedence 7 111

IP Acclamation Practice 38

Table 12-3 Absence and Class Selector DSCP Values

Table 12-5 Appearance Acreage Summary

Table 12-9 RFC-Recommended Ethics for Marking

DSCP Class

Selector Names

Binary DSCP

Values

IPP Binary

Values IPP Names

Default/CS0* 000000 000 Routine

CS1 001000 001 Priority

CS2 010000 010 Immediate

CS3 011000 011 Flash

CS4 100000 100 Flash Override

CS5 101000 101 Critic/Critical

CS6 110000 110 Internetwork Control

CS7 111000 111 Arrangement Control

Field Location Length

IP Antecedence (IPP) IP attack 3 bits

IP DSCP IP attack 6 bits

DS acreage IP attack 1 byte

ToS byte IP attack 1 byte

CoS ISL and 802.1Q attack 3 bits

Discard Eligible (DE) Anatomy Relay attack 1 bit

Cell Loss Antecedence (CLP) ATM corpuscle attack 1 bit

MPLS Experimental MPLS attack 3 bits

Type of Cartage CoS IPP DSCP

Voice burden 5 5 EF

Video burden 4 4 AF41

Voice/video signaling 3 3 CS3

Mission-critical abstracts 3 3 AF31, AF32, AF33

Transactional abstracts 2 2 AF21, AF22, AF23

Bulk abstracts 1 1 AF11, AF12, AF13

Best accomplishment 0 0 BE

Scavenger (less than best effort) 0 0 2, 4, 6

39 CCIE Acquisition and Switching Exam Certification Guide

Table 12-10 Area to Use the qos pre-classify Command

Chapter 13

Table 13-2 Key Comparison Points for Queuing Tools

Table 13-3 CBWFQ Functions and Features

1 Cisco 7500 alternation routers abutment FIFO or WFQ in all the CBWFQ queues.

Configuration Command Under Which

qos pre-classify Is Configured VPN Type

interface adit GRE and IPIP

interface virtual-template L2F and L2TP

crypto map IPsec

Feature Definition

Classification The adeptness to attending at packet headers to accept the appropriate chain for

each packet

Drop action The rules acclimated to accept which packets to bead as queues activate to

fill

Scheduling The argumentation acclimated to actuate which packet should be dequeued next

Maximum cardinal of queues Defines the cardinal of altered classes of packets for a queuing tool

Maximum chain breadth The best cardinal of packets in a distinct queue

CBWFQ Feature Description

Classification Classifies based on annihilation that MQC commands can match

Drop action Tail bead or WRED, configurable per queue

Number of queues 64

Maximum chain breadth Varies based on router archetypal and memory

Scheduling central a distinct chain FIFO on 63 queues; FIFO or WFQ on class-default queue1

Scheduling amid all queues Aftereffect of the scheduler provides a allotment of guaranteed

bandwidth to anniversary queue

IP Acclamation Practice 40

Table 13-5 Reference for CBWFQ Bandwidth Reservation

Table 13-6 Queuing Agreement Comparison

1 WFQ can be acclimated in the class-default chain or in all CBWFQ queues in 7500 alternation routers.

Table 13-7 WRED Abandon Categories

Method

Amount of Bandwidth

Reserved by the bandwidth

Command

The Sum of Ethics in a Single

Policy Map Charge Be <= …

Explicit bandwidth As listed in commands max-res [ts] int-bw

Percent A allotment of the int-bw max-res setting

Remaining percent A allotment of the reservable

bandwidth (int-bw × max-res)

100

Feature CBWFQ LLQ

Includes a strict-priority chain No Yes

Polices antecedence queues to anticipate starvation No Yes

Reserves bandwidth per chain Yes Yes

Includes able-bodied set of allocation fields Yes Yes

Classifies based on flows Yes1 Yes1

Supports RSVP Yes Yes

Maximum cardinal of queues 64 64

Average Chain Depth

Versus Thresholds Action

WRED Name

for Action

Average <>

Minimum beginning <>

depth <>

A allotment of packets dropped. Drop

percentage increases from 0 to a maximum

percent as the boilerplate abyss moves from the

minimum beginning to the maximum.

Random drop

Average abyss > maximum

threshold

All new packets discarded; agnate to tail

drop.

Full drop

41 CCIE Acquisition and Switching Exam Certification Guide

Table 13-9 Comparison of Cisco 3550 and 3560 Queuing Options

Chapter 14

Table 14-2 Abstraction Terminology

Feature Description 3550 3560

Number of admission queues 1 2

Number of departure queues 4 4

Queue cardinal of accelerate chain 4 Configurable

Granularity for ambience chain weights Interface Interface

Frames classified into queues based on… CoS CoS

Granularity for CoS-to-queue mapping Interface Interface

Expedite chain enabled via priority-queue out interface

subcommand

Yes Yes

Ingress policers per anchorage Fast Ethernet/Gigabit Ethernet 8/128 64/64

QoS departure adjustment Policing Abstraction or

policing

Congestion abstention method/number of thresholds per chain WRR/2 WTD/3

Default scheduler WRR SRR

Drop action WRED WTD

Term Definition

Tc Time interval, abstinent in milliseconds, over which the committed access (Bc) can be

sent. With abounding abstraction tools, Tc = Bc/CIR.

Bc Committed access size, abstinent in bits. This is the bulk of cartage that can be sent

during the Tc interval. About authentic in the cartage contract.

CIR Committed advice rate, in $.25 per second, which defines the amount of a VC

according to the business contract.

Shaped

rate

The rate, in $.25 per second, to which a accurate agreement wants to appearance the

traffic. It may or may not be set to the CIR.

Be Excess access size, in bits. This is the cardinal of $.25 above Bc that can be beatific afterwards a

period of inactivity.

IP Acclamation Practice 42

Table 14-3 CB Abstraction Adding of Absence Variable Settings

Table 14-4 Policing Accomplishments Acclimated CB Policing

Table 14-5 Single-Rate, Two-Color Policing Logic for Categorizing Packets

Table 14-6 Single-Rate Three-Color Policing Logic for Categorizing Packets

Variable Amount <= 320 kbps Amount > 320 kbps

Bc 8000 $.25 Bc = abstraction amount * Tc

Be Be = Bc = 8000 Be = Bc

Tc Tc = Bc/shaping amount 25 ms

Command Advantage Approach and Function

drop Drops the packet

set-dscp-transmit Sets the DSCP and transmits the packet

set-prec-transmit Sets the IP Precedence (0 to 7) and sends the packet

set-qos-transmit Sets the QoS Accumulation ID (1 to 99) and sends the packet

set-clp-transmit Sets the ATM CLP bit (ATM interfaces only) and sends the packet

set-fr-de Sets the Anatomy Relay DE bit (Frame Relay interfaces only) and

sends the packet

transmit Sends the packet

Category Requirements Tokens Drained from Bucket

Conform If Xp <= Xb Xp tokens

Exceed If Xp > Xb None

Category Requirements Tokens Drained from Bucket

Conform Xp <= Xbc Xp tokens from the Bc bucket

Exceed Xp > Xbc and Xp <= Xbe Xp tokens from the Be bucket

Violate Xp > Xbc and Xp > Xbe None

43 CCIE Routing and Switching Exam Certification Guide

Table 14-7 Two-Rate, Three-Color Policing Logic for Categorizing Packets

Table 14-8 Setting CB Policing Bc and Be Defaults

Chapter 15

Table 15-2 Anatomy Relay LMI Types

Table 15-3 Anatomy Relay FECN, BECN, and DE Summary

Category Requirements Tokens Drained from Bucket

Conform Xp <= Xbc Xp tokens from the Bc brazier AND

Xp tokens from the Be bucket

Exceed Xp > Xbc and Xp <= Xbe Xp tokens from the Be bucket

Violate Xp > Xbc and Xp > Xbe None

Type of Policing

Configuration

Telltale Signs in the police

Command Defaults

Single rate, two blush No violate-action configured Bc = CIR/32; Be = 0

Single rate, three blush violate-action is configured Bc = CIR/32; Be = Bc

Dual rate, three blush PIR is configured Bc = CIR/32; Be =

PIR/32

LMI Type Antecedent Document

Cisco IOS lmitype

Parameter

Allowed DLCI

Range (Number)

LMI

DLCI

Cisco Proprietary Cisco 16–1007 (992) 1023

ANSI T1.617 Annex D Ansi 16–991 (976) 0

ITU Q.933 Annex A q933a 16–991 (976) 0

Bit Acceptation Back Set Where Set

FECN Congestion in the aforementioned administration as this anatomy By FR switches in user frames

BECN Congestion in the adverse administration of this

frame

By FR switches or routers in

user or Q.922 analysis frames

DE This anatomy should be alone afore non-DE

frames

By routers or switches in user

frames

IP Acclamation Practice 44

Table 15-4 FR Burden Compression Feature Comparison

Table 15-5 Comparing Legacy and Interface FRF.12

Table 15-6 Protocols and Standards for Chapter 15

Feature Packet-by-Packet FRF.9 Data-Stream

Uses LZS algorithm? Yes Yes Yes

Same concordance for all packets? No Yes Yes

Cisco-proprietary? Yes No Yes

Feature Legacy FRF.12

FRF.12 on the

Interface

Requires FRTS? Yes No

Interleaves by agriculture Dual FIFO interface high

queue from a abstraction PQ?

Yes No

Interleaves by appliance either Dual FIFO or a configured

LLQ policy-map on the concrete interface.

No Yes

Config approach for the frame-relay fragment

command.

map-class Concrete interface

Topic Standard

Frame Relay Encapsulation RFC 2427

Frame Relay Compression FRF.9

Frame Relay LFI FRF.12, FRF.11-c

Frame Relay Account Interworking FRF.8

45 CCIE Routing and Switching Exam Certification Guide

Chapter 16

Table 16-2 Some Well-Known Aloof Multicast Addresses

Table 16-3 Multicast Abode Ranges and Their Use

Address Usage

224.0.0.1 All multicast hosts

224.0.0.2 All multicast routers

224.0.0.4 DVMRP routers

224.0.0.5 All OSPF routers

224.0.0.6 OSPF appointed routers

224.0.0.9 RIPv2 routers

224.0.0.10 EIGRP routers

224.0.0.13 PIM routers

224.0.0.22 IGMPv3

224.0.0.25 RGMP

224.0.1.39 Cisco-RP-Announce

224.0.1.40 Cisco-RP-Discovery

Multicast Abode Ambit Usage

224.0.0.0 to 239.255.255.255 This ambit represents the absolute IPv4 multicast abode space. It

is aloof for multicast applications.

224.0.0.0 to 224.0.0.255 This ambit is allotment of the abiding groups. Addresses from this

range are assigned by IANA for arrangement protocols on a local

segment. Routers do not advanced packets with destination

addresses acclimated from this range.

224.0.1.0 to 224.0.1.255 This ambit is additionally allotment of the abiding groups. Addresses

from this ambit are assigned by IANA for the network

protocols that are forwarded in the absolute network. Routers

forward packets with destination addresses acclimated from this

range.

232.0.0.0 to 232.255.255.255 This ambit is acclimated for SSM applications.

233.0.0.0 to 233.255.255.255 This ambit is alleged the GLOP addressing. It is acclimated for

automatically allocating 256 multicast addresses to any

enterprise that owns a registered ASN.

239.0.0.0 to 239.255.255.255 This ambit is acclimated for clandestine multicast domains. These

addresses are alleged administratively scoped addresses.

Remaining ranges of addresses

in the multicast abode space

Addresses from these ranges are alleged brief groups. Any

enterprise can admeasure a multicast abode from the transient

groups for a all-around multicast application, and should absolution it

when the appliance is no best in use.

IP Acclamation Practice 46

Table 16-4 Important IGMPv2 Timers

Table 16-5 Comparison of IGMPv1, IGMPv2, and IGMPv3

Timer Usage Absence Value

Query Breach A time aeon amid Accepted Queries beatific by a

router.

125 seconds

Query Response

Interval

The best acknowledgment time for hosts to acknowledge to

the alternate accepted Queries.

10 seconds; can be

between .1 and

25.5 seconds

Group

Membership

Interval

A time aeon during which, if a router does not

receive an IGMP Report, the router concludes that

there are no added associates of the accumulation on the

subnet.

260 seconds

Other Querier

Present Interval

A time aeon during which, if the IGMPv2 nonquerier

routers do not accept an IGMP Concern from

the querier router, the non-querier routers conclude

that the querier is dead.

255 seconds

Last Member

Query Interval

The best acknowledgment time amid by IGMPv2

routers into the Group-Specific Queries and the time

period amid two afterwards Group-Specific

Queries beatific for the aforementioned group.

1 second

Version 1

Router Present

Timeout

A time aeon during which, if an IGMPv2 host does

not accept an IGMPv1 Query, the IGMPv2 host

concludes that there are no IGMPv1 routers present

and starts sending IGMPv2 messages.

400 seconds

Feature IGMPv1 IGMPv2 IGMPv3

First Octet Amount for the Query

Message

0x11 0x11 0x11

Group Abode for the General

Query

0.0.0.0 0.0.0.0 0.0.0.0

Destination Abode for the General

Query

224.0.0.1 224.0.0.1 224.0.0.1

Default Concern Breach 60 abnormal 125 abnormal 125 seconds

First Octet Amount for the Report 0x12 0x16 0x22

Group Abode for the Report Joining

multicast group

address

Joining

multicast group

address

Joining multicast

group abode and

source address

Destination Abode for the Report Joining

multicast group

address

Joining

multicast group

address

224.0.0.22

47 CCIE Routing and Switching Exam Certification Guide

Table 16-5 Comparison of IGMPv1, IGMPv2, and IGMPv3

Is Report Suppression Mechanism

Available?

Yes Yes No

Can Best Acknowledgment Time Be

Configured?

No, anchored at 10

seconds

Yes, 0 to 25.5

seconds

Yes, 0 to 53

minutes

Can a Host Accelerate a Leave Group

Message?

No Yes Yes

Destination Abode for the Leave

Group Message

224.0.0.2 224.0.0.22

Can a Router Accelerate a Group-Specific

Query?

No Yes Yes

Can a Host Accelerate Source- and

Group-Specific Reports?

No No Yes

Can a Router Accelerate Source- and

Group-Specific Queries?

No No Yes

Rule for Electing a Querier None—

depends on

multicast

routing

protocol

Router with the

lowest IP

address on the

subnet

Router with the

lowest IP address

on the subnet

Compatible with Added Versions of

IGMP?

No Yes, alone with

IGMPv1

Yes, with both

IGMPv1 and

IGMPv2

IP Acclamation Practice 48

Chapter 17

Table 17-2 Summary of PIM-DM Messages

Table 17-3 Comparison of Methods of Finding the RP

PIM Bulletin Definition

Hello Acclimated to anatomy acquaintance adjacencies with added PIM routers, and to maintain

adjacencies by ecology for accustomed Hellos from anniversary neighbor. Additionally acclimated to

elect a PIM DR on multiaccess networks.

Prune Acclimated to ask a adjoining router to abolish the articulation over which the Prune flows

from that adjoining router’s approachable interface account for a accurate (S,G) SPT.

State Refresh Acclimated by a afterwards router, beatific to an upstream router on an RPF interface,

to account the upstream router to displace its Prune timer. This allows the

downstream router to advance the pruned accompaniment of a link, for a accurate (S,G)

SPT.

Assert Acclimated on multiaccess networks to actuate which router wins the appropriate to

forward multicasts assimilate the LAN, for a accurate (S,G) SPT.

Prune Override

(Join)

On a LAN, a router may multicast a Prune bulletin to its upstream routers.

Other routers on the aforementioned LAN, absent to anticipate the upstream router from

pruning the LAN, anon accelerate addition Accompany bulletin for the (S,G) SPT.

(The Prune Override is not absolutely a Prune Override message—it is a Join.

This is the alone purpose of a Accompany bulletin in PIM-DM, per RFC 3973.)

Graft/Graft-Ack Back a pruned articulation needs to be added aback to an (S,G) SPT, a router sends a

Graft bulletin to its RPF neighbor. The RPF acquaintance acknowledges with a

Graft-Ack.

Method RP Details Mapping Info

Redundant

RP Support?

Load

Sharing of

One Group?

Static Simple advertence to

unicast IP address.

No No

Auto-RP Sends RP-Announce

to 224.0.1.39; relies

on sparse-dense

mode.

Mapping abettor sends

via RP-Discovery to

224.0.1.40

Yes No

BSR Sends c-RP

advertisements as

unicasts to BSR IP

address; does not

need sparse-dense

mode.

Sends bootstrap

messages abounding over

non-RPF path

Yes No

Anycast

Each RP uses

identical IP

addresses.

Can use Auto-RP or

BSR accustomed processes

Yes Yes

49 CCIE Routing and Switching Exam Certification Guide

Table 17-4 Comparison of PIM-DM and PIM-SM

Feature PIM-DM PIM-SM

Destination abode for Version

1 Concern messages, and IP

protocol number

224.0.0.2 and 2 224.0.0.2 and 2

Destination abode for Version

2 Hello messages, and IP

protocol number

224.0.0.13 and 103 224.0.0.13 and 103

Default breach for Concern and

Hello messages

30 abnormal 30 seconds

Default Holdtime for Versions 1

and 2

90 abnormal 90 seconds

Rule for electing a designated

router on a multiaccess network

Router with the accomplished IP

address on the subnet

Router with the accomplished IP

address on the subnet

Main architecture assumption A router automatically

receives the traffic. If it does

not appetite the traffic, it has to

say no (send a Prune message)

to its sender.

Unless a router specifically

makes a appeal to an RP, it

does not accept multicast

traffic.

SPT or RPT? Uses alone SPT First uses RPT and then

switches to SPT

Uses Join/Prune messages? Yes Yes

Uses Graft and Graft-Ack

messages?

Yes No

Uses Prune Override

mechanism?

Yes Yes

Uses Assert message? Yes Yes

Uses RP? No Yes

Uses antecedent registration

process?

No Yes

IP Acclamation Practice 50

Table 17-7 mroute Flags

Flag Description

D (dense) Admission is operating in close mode.

S (sparse) Admission is operating in dispersed mode.

(connected)

A affiliate of the multicast accumulation is present on the anon affiliated interface.

L (local) The router itself is a affiliate of the multicast group.

P (pruned) Route has been pruned.

R (RP-bit

set)

Indicates that the (S,G) admission is pointing against the RP. The RP is about in a

pruned accompaniment forth the aggregate timberline afterwards a afterwards router has switched to SPT for

a accurate source.

F (register

flag)

Indicates that the software is registering for a multicast source.

Flag Description

T (SPT-bit

set)

Indicates that packets accept been accustomed on the shortest-path antecedent tree.

J (join SPT) This banderole has acceptation alone for sparse-mode groups. For (*,G) entries, the J flag

indicates that the amount of cartage abounding bottomward the aggregate timberline has exceeded the SPTThreshold

set for the group. This adding is done already a second. On Cisco

routers, the absence SPT-Threshold amount is 0 kbps. Back the J banderole is set on the (*,G)

entry and the router has a anon affiliated accumulation affiliate denoted by the C flag,

the abutting (S,G) packet accustomed bottomward the aggregate timberline will activate a about-face over from

RPT to SPT for antecedent S and accumulation G.

For (S,G) entries, the J banderole indicates that the admission was created because the router

has switched over from RPT to SPT for the group. Back the J banderole is set for the

(S,G) entries, the router monitors the cartage amount on SPT and switches aback to RPT

for this antecedent if the cartage amount on the antecedent timberline avalanche beneath the group’s

SPT-Threshold for added than 1 minute.

51 CCIE Routing and Switching Exam Certification Guide

Chapter 18

Table 18-2 Comparing RADIUS and TACACS+ for Authentication

1Radius originally authentic anchorage 1645 as the acclaimed port, which was after afflicted to anchorage 1812.

Table 18-3 Affidavit Methods for Login and Enable

1Cannot be acclimated for accredit authentication.

RADIUS TACACS+

Scope of Encryption: packet burden or aloof the

password

Password alone Absolute payload

Layer 4 Protocol UDP TCP

Well-Known Port/IOS Absence Anchorage Acclimated for

authentication

1812/16451 49/49

Standard or Cisco-Proprietary RFC 2865 Proprietary

Method Meaning

group ambit Use the configured RADIUS servers

group tacacs+ Use the configured TACACS+ servers

group name Use a authentic accumulation of either RADIUS or TACACS+ servers

enable Use the accredit password, based on accredit abstruse or accredit password

commands

line1 Use the countersign authentic by the countersign command in line

configuration mode

local Use username commands in the bounded configuration; treats the

username as case insensitive, but the countersign as case sensitive

local-case Use username commands in the bounded configuration; treats both the

username and countersign as case sensitive

none No affidavit required; user is automatically authenticated

IP Acclamation Practice 52

Table 18-4 Anchorage Aegis Configuration Commands

Table 18-5 Cisco IOS About-face Dynamic ARP Analysis Commands

Command Purpose

switchport approach {access | trunk} Anchorage aegis requires that the anchorage be statically set as either

access or trunking

switchport port-security

[maximum value]

Enables anchorage aegis on an interface, and optionally

defines the cardinal of accustomed MAC addresses on the port

(default 1)

switchport port-security macaddress

mac-address [vlan {vlanid

| {access | voice}}]

Statically defines an accustomed MAC address, for a particular

VLAN (if trunking), and for either the admission or voice

VLAN

switchport port-security macaddress

sticky

Tells the about-face to bethink the dynamically learned

MAC addresses

switchport port-security [aging]

[violation {protect | bind |

shutdown}]

Defines the Crumbling timer and accomplishments taken back a violation

occurs

Command Purpose

ip arp analysis vlan vlan-range All-around command to accredit DAI on this about-face for the

specified VLANs.

[no] ip arp analysis assurance Interface subcommand that enables (with no option) or

disables DAI on the interface. Defaults to enabled once

the ip arp analysis all-around command has been

configured.

ip arp analysis clarify arp-acl-name

vlan vlan-range [static]

Global command to accredit to an ARP ACL that defines

static IP/MAC addresses to be arrested by DAI for that

VLAN (Step 2 in the above-mentioned list).

ip arp analysis validate {[src-mac]

[dst-mac] [ip]}

Enables added alternative blockage of ARP messages

(per Steps 35 in the above-mentioned list).

ip arp analysis absolute {rate pps

[burst breach seconds] | none}

Limits the ARP bulletin amount to anticipate DoS attacks

carried out by sending a ample cardinal or ARPs.

53 CCIE Routing and Switching Exam Certification Guide

Table 18-6 Cisco IOS About-face Dynamic ARP Analysis Commands

Chapter 19

Table 19-2 MPLS LSR Terminology Reference

Command Purpose

ip dhcp concern vlan vlan-range All-around command to accredit DHCP concern for one or

more VLANs

[no] ip dhcp concern assurance Interface command to accredit or attenuate a assurance akin on

an interface; no adaptation (enabled) is the default

ip dhcp concern bounden mac-address

vlan vlan-id ip-address interface

interface-id accomplishment seconds

Global command to add changeless entries to the DHCP

snooping bounden database

ip dhcp concern verify mac-address Interface subcommand to add the alternative analysis of

the Ethernet antecedent MAC abode to be according to a

DHCP request’s applicant ID

ip dhcp concern absolute amount amount Sets the best cardinal of DHCP letters per

second to abate DoS attacks

LSR Type Accomplishments Performed by This LSR Type

Label About-face Router (LSR) Any router that pushes labels assimilate packets, ancestor labels from packets,

or artlessly assiduously labeled packets.

Edge LSR (E-LSR) An LSR at the bend of the MPLS network, acceptation that this router

processes both labeled and unlabeled packets.

Ingress E-LSR For a accurate packet, the router that receives an unlabeled packet

and again inserts a characterization assemblage in advanced of the IP header.

Egress E-LSR For a accurate packet, the router that receives a labeled packet and

then removes all MPLS labels, forwarding an unlabeled packet.

ATM-LSR An LSR that runs MPLS protocols in the ascendancy even to set up

ATM basic circuits. Assiduously labeled packets as ATM cells.

ATM E-LSR An bend LSR that additionally performs the ATM Segmentation and

Reassembly (SAR) function.

IP Acclamation Practice 54

Table 19-3 MPLS Attack Fields

Table 19-4 LDP Reference

Field Length (Bits) Purpose

Label 20 Identifies the allocation of a characterization switched aisle (LSP).

Experimental (EXP) 3 Acclimated for QoS marking; the acreage is no best acclimated for

truly beginning purposes.

Bottom-of-Stack (S) 1 Flag, which back set to 1, agency that this is the label

immediately above-mentioned the IP header.

Time-to-Live (TTL) 8 Acclimated for the aforementioned purposes as the IP header’s TTL field.

LDP Feature LDP Implementation

Transport protocols UDP (Hellos), TCP (updates)

Port numbers 646 (LDP), 711 (TDP)

Hello destination abode 224.0.0.2

Who initiates TCP

connection

Highest LDP ID

TCP affiliation uses this

address

Transport IP abode (if configured), or LDP ID if no transport

address is configured

LDP ID bent by

these rules, in adjustment or

precedence

Configuration

Highest IP abode of an up/up loopback back LDP comes up

Highest IP abode of an up/up non-loopback back LDP comes up

55 CCIE Routing and Switching Exam Certification Guide

Chapter 20

Table 20-2 IPv6 Abode Types

Table 20-3 IPv6 Multicast Well-Known Addresses

Address Type Ambit Application

Aggregatable global

unicast

2000::/3 Host-to-host communication; aforementioned as IPv4 unicast.

Multicast FF00::/8 One-to-many and many-to-many communication; same

as IPv4 multicast.

Anycast Aforementioned as

Unicast

Application-based, including amount balancing, optimizing

traffic for a accurate service, and redundancy. Relies on

routing metrics to actuate the best destination for a

particular host.

Link-local unicast FE80::/10 Connected-link communications.

Solicited-node

multicast

FF02::1:FF00

:0/104

Neighbor solicitation.

Function Multicast Accumulation IPv4 Equivalent

All hosts FF02::1 Subnet advertisement address

All routers FF02::2 224.0.0.2

OSPFv3 routers FF02::5 224.0.0.5

OSPFv3 appointed routers FF02::6 224.0.0.6

EIGRP routers FF02::A 224.0.0.10

PIM routers FF02::D 224.0.0.13

IP Acclamation Practice 56

Table 20-4 Acquaintance Discovery Functions in IPv6

Message Type

Information

Sought or Beatific Antecedent Address

Destination

Address

ICMP

Type,

Code

Router

(RA)

Routers advertise

their attendance and

link prefixes, MTU,

and hop limits.

Router’s link-local

address

FF02::1 for periodic

broadcasts; address

of querying host for

responses to an RS

134, 0

Router

Solicitation (RS)

Hosts concern for the

presence of routers

on the link.

Address assigned

to querying

interface, if

assigned, or :: if not

assigned

FF02::2 133, 0

Neighbor

Solicitation (NS)

Hosts concern for

other nodes’ linklayer

addresses.

Used for duplicate

address detection

and to verify

neighbor

reachability.

Address assigned

to querying

interface, if

assigned, or :: if not

assigned

Solicited-node

multicast abode or

the ambition node’s

address, if known

135, 0

Neighbor

(NA)

Sent in acknowledgment to

NS letters and

periodically to

provide information

to neighbors.

Configured or

automatically

assigned abode of

originating

interface

Address of node

requesting the NA or

FF02::1 for periodic