This area lists added capacity and facts to annular out the advantage of the capacity in this chapter.
Unlike best of the Cisco Press Assay Certification Guides, this “Foundation Summary” does not
repeat advice presented in the “Foundation Topics” area of the chapter. Please booty the
time to apprehend and abstraction the capacity in the “Foundation Topics” area of the chapter, as able-bodied as
review items acclaimed with a Key Topic icon.
Table 17-5 lists the agreement standards referenced in this chapter.
Table 17-6 lists some of the best accustomed Cisco IOS commands accompanying to the capacity in this
chapter and Affiliate 16.
Table 17-5 RFC Reference for Affiliate 20
RFC What It Defines
3973 PIM-DM
3618 MSDP
3446 Anycast RP
2362 PIM-SM
1584 Multicast Extensions to OSPF
Table 17-6 Command Reference for Chapters 16 and 17
Command Command Approach and Description
ip multicast-routing Global mode; appropriate aboriginal command on Cisco routers to use
multicasting.
ip pim dense-mode1 Interface config mode; configures the interface to use PIM-DM
routing protocol.
ip pim sparse-mode1 Interface config mode; configures the interface to use PIM-SM
routing protocol.
ip pim sparse-dense-mode Interface config mode; configures the interface to use PIM-SM
routing agreement for a accumulation if the RP abode is known;
otherwise, uses PIM-DM acquisition protocol.
Foundation Arbitrary 635
Command Command Approach and Description
ip igmp adaptation {1 | 2} Interface config mode; sets the IGMP adaptation on an interface. The
default is 2.
ip igmp query-interval abnormal Interface config mode; changes the breach for IGMP queries
sent by the router from the absence 60 seconds.
ip igmp query-max-responsetime
seconds
Interface config mode; changes the Max Response Time
advertised in IGMP Queries from the absence of 10 abnormal for
IGMPv2 and IGMPv3.
ip igmp join-group group-address Interface config mode; configures a router to accompany a multicast
group. The group-address is a multicast IP abode in four-part
dotted-decimal notation.
ip multicast abuttals access-list
[filter-autorp]
Interface config mode; configures an interface as a multicast
boundary for authoritative scoping. A numbered or named
access account controls the ambit of accumulation addresses afflicted by the
boundary. (Optional) filter-autorp filters Auto-RP messages
denied by the abuttals ACL.
ip multicast ttl-threshold ttl-value Interface config mode; configures an interface as a multicast
boundary for TTL scoping. Time-to-Live amount represents
number of hops, alignment from 0 to 255. The absence amount is 0,
which agency that all multicast packets are forwarded out the
interface.
ip cgmp Interface config mode; enables abutment for CGMP on an
interface.
ip pim adaptation {1 | 2} Interface config mode; sets the PIM adaptation on an interface. The
default is 2.
ip pim query-interval abnormal Interface config mode; changes the breach for PIMv2 Hello or
PIMv1 Router Query letters from the absence 60 seconds.
ip pim message-interval abnormal Interface config mode; changes the breach for sparse-mode Join/
Prune letters from the absence 60 seconds.
ip pim spt-threshold {kbps |
infinity} [group-list access-listnumber]
Global mode; specifies the admission amount for the multicast traffic
for a PIM-SM router to about-face from RPT to SPT. The absence is to
switch afterwards the aboriginal multicast packet is received. If the group-list
option is used, the command ambit are activated alone to the
groups acceptable by the admission list; otherwise, they are activated to
all groups.
Table 17-6 Command Reference for Chapters 16 and 17 (Continued)
continues
636 Affiliate 17: IP Multicast Routing
Command Command Approach and Description
ip pim rp-address rp-address
[access-list] [override]
Global mode; statically configures the IP abode of an
RP area rp-address is a unicast IP abode in four-part,
dotted notation. (Optional) access-list represents a cardinal or
name of an admission account that defines for which multicast groups
the RP should be used. (Optional) override indicates that if
there is a conflict, the RP configured with this command
prevails over the RP abstruse dynamically by Auto-RP or any
other method.
ip pim send-rp-announce
interface-type interface-number
scope ttl-value [group-list accesslist]
[interval seconds]
Global mode; configures the router to be an RP, and the router
sends RP-Announce letters application the Auto-RP adjustment for the
interface abode selected. Ambit represents the TTL. (Optional)
group-list defines the multicast groups for which this router is
RP. (Optional) breach changes the advertisement frequency
from the absence 60 seconds.
ip pim send-rp-discovery
[interface-type interface-number]
scope ttl-value
Global mode; configures the router to be a mapping agent, and
the router sends RP-Discovery letters application the Auto-RP
method. ambit represents the TTL. (Optional) The IP abode of
the interface defined is acclimated as the antecedent abode for the
messages. The absence is to use the IP abode of the interface on
which the bulletin is beatific as the antecedent address.
ip pim rp-announce-filter rp-list
access-list group-list access-list
Global mode; configures a mapping abettor to clarify RPAnnounce
messages advancing from specific RPs. rp-list accesslist
specifies a cardinal or name of a accustomed admission account that
specifies that this clarify is alone for the RP addresses acceptable in
this ACL. group-list access-list specifies a cardinal or name of a
standard admission account that describes acceptable accumulation addresses.
The clarify defines that alone the accumulation ambit acceptable in the
group-list access-list should be accustomed from the RPAnnouncements
received from the RP addresses acceptable by
the rp-list access-list.
show ip igmp groups [group-name
| group-address | interface-type
interface-number] [detail]
User mode; displays the account of multicast groups for which the
router has anon affiliated accumulation members, abstruse via IGMP.
show ip mroute [group-address |
group-name] [source-address |
source-name] [interface-type
interface-number] [summary]
[count] [active kbps]
User mode; displays the capacity of the IP multicast acquisition table.
Table 17-6 Command Reference for Chapters 16 and 17 (Continued)
Foundation Arbitrary 637
Table 17-7 summarizes important flags displayed in an mroute access aback you use the command
show ip mroute.
Command Command Approach and Description
show ip pim acquaintance [interfacetype
interface-number]
User mode; displays the account of neighbors apparent by PIM.
show ip pim rp [mapping [elected
| in-use] | metric] [rp-address]
User mode; displays the alive RPs associated with multicast
groups.
show ip rpf {source-address |
source-name} [metric]
User mode; displays the advice IP multicasting acquisition uses
to accomplish the RPF check.
clear ip cgmp [interface-type
interface-number]
Enable mode; the router sends a CGMP Leave bulletin and
instructs the switches to bright all accumulation entries they have
cached.
debug ip igmp Enable mode; displays IGMP letters accustomed and sent, and
IGMP-host-related events.
debug ip pim Enable mode; displays PIM letters accustomed and sent, and
PIM-related events.
1When you configure any one of these commands on a LAN interface, IGMPv2 is automatically enabled on the
interface.
Table 17-7 mroute Flags
Flag Description
D (dense) Access is operating in close mode.
S (sparse) Access is operating in dispersed mode.
C (connected) A affiliate of the multicast accumulation is present on the anon connected
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) access is pointing against the RP. The RP is about in
a pruned accompaniment forth the aggregate timberline afterwards a after router has switched to
SPT for a accurate source.
F (register flag) Indicates that the software is registering for a multicast source.
Table 17-6 Command Reference for Chapters 16 and 17 (Continued)
continues
638 Affiliate 17: IP Multicast Routing
Memory Builders
The CCIE Acquisition and Switching accounting exam, like all Cisco CCIE accounting exams, covers a fairly
broad set of topics. This area provides some basal accoutrement to advice you exercise your anamnesis about
some of the broader capacity covered in this chapter.
Fill in Key Tables from Memory
Appendix E, “Key Tables for CCIE Study,” on the CD in the aback of this book contains abandoned sets
of some of the key arbitrary tables in anniversary chapter. Print Appendix E, accredit to this chapter’s tables
in it, and ample in the tables from memory. Accredit to Appendix F, “Solutions for Key Tables for CCIE
Study,” on the CD to analysis your answers.
Flag Description
T (SPT-bit set) Indicates that packets accept been accustomed on the shortest-path source
tree.
J (join SPT) This banderole has acceptation alone for sparse-mode groups. For (*,G) entries, the
J banderole indicates that the amount of cartage abounding bottomward the aggregate timberline has
exceeded the SPT-Threshold set for the group. This adding is done already a
second. On Cisco routers, the absence SPT-Threshold amount is 0 kbps. When
the J banderole is set on the (*,G) access and the router has a anon connected
group affiliate denoted by the C flag, the abutting (S,G) packet accustomed bottomward the
shared timberline will activate a about-face over from RPT to SPT for antecedent S and
group G.
For (S,G) entries, the J banderole indicates that the access was created because the
router has switched over from RPT to SPT for the group. Aback 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 falls
below the group’s SPT-Threshold for added than 1 minute.
Table 17-7 mroute Flags
Memory Builders 639
Definitions
Next, booty a few moments to address bottomward the definitions for the afterward terms:
dense-mode protocol, RPF check, sparse-mode protocol, RP, multicast scoping, TTL scoping,
administrative scoping, PIM-DM, PIM Hello message, appointed router, source-based
distribution tree, multicast accompaniment information, Join/Prune message, upstream router, downstream
router, Graft message, Graft Ack message, Prune Override, Assert message, DVMRP, MOSPF,
PIM-SM, antecedent DR, antecedent registration, aggregate administration tree, shortest-path timberline switchover,
PIM-SM (S, G) RP-bit Prune, Auto-RP
Refer to the comment to analysis your answers.
Further Reading
Developing IP Multicast Networks, Volume I, by Beau Williamson (Cisco Press, 2000).