Showing Multicast Status
Problem
You appetite to appearance the accepted cachet of multicast protocols on your router.
Solution
There are several advantageous commands for blockage the cachet of multicast agreement and protocols. You can see what multicast routes canyon through a router with the EXEC command:
Router#show ip mroute
There are two advantageous variants of this command. The aboriginal letters on forwarding statistics for anniversary multicast group:
Router#show ip mroute count
And the additional letters alone on the groups that are currently active:
Router#show ip mroute active
You can attending at statistics on accumulation associates appliance the command:
Router#show ip igmp groups
Use the interface keyword to attending at the IGMP advice in added detail:
Router#show ip igmp interface
There are four advantageous commands for examination PIM information. The aboriginal shows advice about PIM acquaintance relationships:
Router#show ip pim neighbor
The additional command shows advice about the PIM agreement on altered interfaces:
Router#show ip pim interface
This command shows advice about PIM-SM Rendezvous Points (RP):
Router#show ip pim rp
And, finally, if you are appliance the Bootstrap Router (PIM Adaptation 2) abode for distributing RP information, you will appetite to use this command:
Router#show ip pim bsr-router
PIMv2 Bootstrap information
This arrangement is the Bootstrap Router (BSR)
BSR address: 172.17.254.5 (?)
Uptime: 00:06:37, BSR Priority: 0, Hash affectation length: 1
Abutting bootstrap bulletin in 00:00:22
Next Cand_RP_advertisement in 00:00:15
RP: 172.17.254.5(Loopback0)
Router#
There are several commands that acquiesce you to attending at MSDP functions:
Router#show ip msdp count
Router#show ip msdp associate 192.168.201.15
Router#show ip msdp summary
You can attending at capacity of the Reverse Path Forwarding copse by appliance two advantageous commands, appearance ip rpf and mstat:
Router#show ip rpf 192.168.3.2
Router#mstat 192.168.3.2 239.5.5.55
Discussion
The appearance ip mroute command gives advice on multicast routing. It shows which interfaces the router will use to advanced packets acceptance to altered groups, and it additionally shows area the sources or Rendezvous Points for these groups are:
Router#show ip mroute
IP Multicast Acquisition Table
Flags: D - Dense, S - Sparse, C - Connected, L - Local, P Pruned
R - RP-bit set, F - Register flag, T - SPT-bit set, J - Accompany SPT
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 224.0.1.40), 03:29:10/00:00:00, RP 0.0.0.0, flags: DJCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Ethernet1, Forward/Sparse-Dense, 03:29:10/00:00:00
(*, 239.5.5.55), 5d06h/00:02:59, RP 0.0.0.0, flags: DJC
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Ethernet0, Forward/Sparse-Dense, 00:04:23/00:00:00
Ethernet1, Forward/Sparse-Dense, 03:29:08/00:00:00
(192.168.5.2/32, 239.5.5.55), 00:00:50/00:02:09, flags: CT
Incoming interface: Ethernet1, RPF nbr 0.0.0.0
Outgoing interface list:
Ethernet0, Forward/Sparse-Dense, 00:00:50/00:00:00
In this example, the router belongs to multicast copse for two groups, 224.0.1.40 and 239.5.5.55. The aboriginal of these groups is what Cisco routers use for the Auto-RP action to locate a Rendezvous Point. In this case, there is no antecedent for this group, but there is a affiliate on the articulation Ethernet1. This accumulation affiliate is addition router that is additionally attractive for the RP.
The additional accumulation has two entries. The aboriginal is the accepted (*,G) entry. The additional is a specific (S,G) admission that shows the alone accepted antecedent for this multicast group, 192. 168.5.2. This specific admission indicates that this antecedent is on the interface Ethernet1, and that there are associates on interface Ethernet0.
The flags at the end of anniversary accumulation admission accord advantageous advice about the forwarding. Both of the accepted (*,G) enTRies accommodate the flags, "D" and "J", which announce that the router is appliance Dense-mode forwarding, and that it has abutting a Shortest Path Tree. This is important because it says that although this router is configured for Sparse-Dense approach forwarding, it has not yet begin an RP, so it is appliance Dense-mode forwarding.
The "C" flag, which you can see in all of the multicast acquisition entries, is for affiliated networks. This is best advantageous in the aftermost admission because it shows that the multicast source, 192.168.5.2, is on a anon affiliated arrangement segment. Since both the antecedent and all of the accumulation associates are on interfaces on the aforementioned router, there is no charge for it to try to accompany a timberline abutting it to added routers.
The added absorbing banderole in this archetype is the "L" flag, which indicates that the router itself is a affiliate of this group. This is accurate for the 224.0.1.40 group, because the router is acquisitive to ascertain the RP by alert to this group.
With the calculation keyword, this command gives statistics on multicast usage:
Router#show ip mroute count
IP Multicast Statistics
3 routes appliance 1776 bytes of memory
2 groups, 0.5 boilerplate sources per group
Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per second
Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc)
Group: 224.0.1.40, Antecedent count: 0, Accumulation pkt count: 0
Group: 239.5.5.55, Antecedent count: 1, Accumulation pkt count: 1
Source: 192.168.5.2/32, Forwarding: 1/0/100/0, Other: 1/0/0
The admission for 239.5.5.55 shows that there is alone one source. It additionally shows that there has alone been one packet associated with this accumulation for all sources. The detail beneath this band break out the packet statistics for anniversary source. The fields assignment as follows:
Source: 192.168.5.2/32, Forwarding: 1/0/100/0, Other: 1/0/0
There are four fields afar by slashes afterward the chat "Forwarding." These represent the absolute cardinal of packets that accept been forwarded, the accepted forwarding amount in packets per second, followed by the boilerplate packet size, and, finally, the forwarding amount in kilobits per second. The three fields afterwards the chat "Other" are the absolute cardinal of packets received, followed by the cardinal of packets that had to be alone for Reverse Path Forwarding failures, and the cardinal of drops for all added reasons. Note that the absolute cardinal of forwarded packets, from the aboriginal cardinal afterwards Fowarding, additional the aftermost two fields afterwards Other, should add up to the aboriginal acreage afterwards Other. These aftermost two fields artlessly accord an adumbration of back packets are alone and why.
The alive keyword shows alone those sources that are currently sending multicast cartage at a amount greater than 4 Kbps:
Router#show ip mroute active
Active IP Multicast Sources - sending >= 4 kbps
Group: 239.5.5.55, (?)
Source: 192.168.5.2 (?)
Rate: 6 pps/41 kbps(1sec), 14 kbps(last 15 secs), 1 kbps(life avg)
Source: 192.168.254.5 (?)
Rate: 2 pps/24 kbps(1sec), 12 kbps(last 15 secs), 1 kbps(life avg)
Router#
This command can be ambiguous because abounding multicast applications accomplish decidedly slower than the minimum 4-Kbps rate. The sources for those slower applications do not appear. However, this can be advantageous for college bandwidth multimedia blazon applications. The achievement shows the ante in both packets per additional (pps) and kilobits per additional (Kbps) averaged over the aftermost second, as able-bodied as the ante in Kbps for the aftermost 15 abnormal and averaged over the absolute activity of this source.
In this accurate case, there are absolutely three sources for this multicast application, but one is beneath the threshold. You can see them all by appliance the afterward command:
Router#show ip mroute 239.5.5.55 count
IP Multicast Statistics
12 routes appliance 4908 bytes of memory
5 groups, 1.40 boilerplate sources per group
Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per second
Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc)
Group: 239.5.5.55, Antecedent count: 3, Accumulation pkt count: 2319
RP-tree: Forwarding: 0/0/0/0, Other: 0/0/0
Source: 192.168.3.2/32, Forwarding: 65/0/76/0, Other: 65/0/0
Source: 192.168.5.2/32, Forwarding: 1127/0/564/0, Other: 1128/1/0
Source: 192.168.254.5/32, Forwarding: 1127/0/564/0, Other: 1127/0/0
Router#
To attending at multicast accumulation associates on the router, use the command:
Router# appearance ip igmp groups
Group Abode Interface Uptime Expires Aftermost Reporter
224.0.1.39 TokenRing0 01:17:44 00:02:59 192.168.3.2
224.0.1.40 Ethernet1 16:02:35 never 192.168.5.1
239.5.5.55 Ethernet0 00:22:07 00:02:50 192.168.1.104
239.5.5.55 TokenRing0 16:02:26 00:02:53 192.168.3.2
224.0.1.1 TokenRing0 16:02:26 00:02:51 192.168.3.2
Router#
This tells you area there are associates for anniversary of the alive groups. The Aftermost Reporter cavalcade tells you the aftermost accepted accumulation affiliate for this group. The router will periodically concern the articulation to accomplish abiding that there are still alive members. The Uptime cavalcade indicates how continued this accumulation has had associates on this segment, and the Expires cavalcade shows back this accumulation will be removed if there are no added associates reports. Note that one of the entries, 224.0.1.40, will never expire. This is because the router itself is a affiliate of this group, as it is acclimated for the Auto-RP process.
With the interface keyword, the appearance ip igmp command gives capacity on how IGMP is implemented on this accurate interface. It tells you advice about IGMP concern periods and what router is the PIM Appointed Router (DR) for the segment. In the afterward example, this router is the DR for the segment. Back there is added than one router on a segment, one of them charge affirmation the role of DR or every multicast packet will arise twice. So this is a advantageous way of addition out which router is DR:
Router# appearance ip igmp interface Ethernet0
Ethernet0 is up, band agreement is up
Internet abode is 192.168.1.201/24
IGMP is enabled on interface
Accepted IGMP adaptation is 2
CGMP is disabled on interface
IGMP concern breach is 60 seconds
IGMP querier abeyance is 120 seconds
IGMP max concern acknowledgment time is 10 seconds
Inbound IGMP admission accumulation is not set
IGMP activity: 2 joins, 0 leaves
Multicast acquisition is enabled on interface
Multicast TTL beginning is 15
Multicast appointed router (DR) is 192.168.1.201 (this system)
IGMP querying router is 192.168.1.201 (this system)
No multicast groups joined
Another advantageous allotment of advice in this archetype is the Multicast TTL beginning indicator. A TTL beginning of 15 has been set on this interface to anticipate bounded multicast cartage from extensive this segment. One of the best accepted problems with multicast networks comes from afield ambience multicast TTL thresholds. This can either acquiesce multicast cartage to aperture out of the adapted arrangement arena or account a router to bead it prematurely.
You can attending at a router's PIM acquaintance table as follows, for IOS Adaptation 11.x:
Router#show ip pim neighbor
PIM Acquaintance Table
Neighbor Abode Interface Uptime Expires Mode
192.168.5.2 Ethernet1 16:22:46 00:01:23 Sparse-Dense (DR)
192.168.3.2 TokenRing0 16:22:16 00:01:05 Sparse-Dense (DR)
Router#
This shows not alone what the PIM acquaintance routers are, but additionally what PIM approach they are appliance (Sparse-Dense for both of the routers in this example), how continued the acquaintance accord has existed, and back the router will annul this acquaintance from its table if it doesn't apprehend from it again. The absolute aftermost acreage in both curve indicates that this router is the DR for both of these arrangement segments. If you attending at the aforementioned advice on either of these acquaintance routers, you will see that neither of them accept this DR indication.
The architecture of this achievement afflicted hardly amid IOS Versions 11.x and 12.x. It now includes PIM adaptation information:
Router#show ip pim neighbor
PIM Acquaintance Table
Neighbor Abode Interface Uptime Expires Ver Mode
192.168.5.1 Ethernet0 16:33:41 00:01:02 v1 Dense
192.168.254.6 Serial0 16:34:23 00:01:38 v2
Router#
As you can see, one of the neighbors is appliance PIM Adaptation 1. This absolutely highlights the interoperability of the altered PIM versions. You can calmly body a amalgam arrangement appliance both old and new routers.
The appearance ip pim interface command looks like this:
Router#show ip pim interface
Address Interface Version/Mode Nbr Concern DR
Calculation Intvl
192.168.5.2 Ethernet0 v2/Sparse-Dense 1 30 192.168.5.2
192.168.254.5 Serial0 v2/Sparse-Dense 1 30 0.0.0.0
Router#
Notice that there are slight differences amid the achievement of this command and the antecedent one. In particular, the interface command indicates that the Ethernet0 anchorage is configured for PIM Adaptation 2 (the default), appliance Sparse-Dense mode. However, the antecedent acquaintance command shows that this anchorage is absolutely appliance Dense approach and PIM Adaptation 1 for affinity with the earlier router.
When appliance PIM-SM, you can see advice about the RPs appliance this command:
Router#show ip pim rp
Group: 239.255.255.250, RP: 192.168.3.2, v2, v1, uptime 00:00:43, expires 00:02:16
Group: 239.5.5.55, RP: 192.168.3.2, v2, v1, uptime 00:00:42, expires 00:02:17
Group: 224.0.1.1, RP: 192.168.3.2, v2, v1, uptime 00:00:42, expires 00:02:17
Router#
Note that you can accept altered RPs for altered groups. So the achievement of this command shows the RP alone for anniversary group. Of course, in this archetype there is alone one RP for the absolute network.
If you are appliance a BSR to administer RP information, as in Recipe 23.2, you can attending at the BSR cachet by appliance the bsr-router keyword:
Router#show ip pim bsr-router
PIMv2 Bootstrap information
This arrangement is the Bootstrap Router (BSR)
BSR address: 172.17.254.5 (?)
Uptime: 00:06:37, BSR Priority: 0, Hash affectation length: 1
Abutting bootstrap bulletin in 00:00:22
Next Cand_RP_advertisement in 00:00:15
RP: 172.17.254.5(Loopback0)
Router#
In this example, the router itself claims to be the BSR for the network. This agency artlessly that it is amenable for distributing RP advice to the network. This command additionally shows what the abutting RP that this router intends to acquaint will be, and back it will accelerate out the abutting advertisement.
If you are active MSDP to administer multicast antecedent and RP advice amid networks, you will appetite to use the assorted appearance ip msdp commands. The calculation keyword allows you to see gross statistics for all of the configured MSDP peers:
Router#show ip msdp count
SA State per Associate Counters,
192.168.199.15: 0
192.168.201.15: 0
SA State per ASN Counters,
Absolute entries: 0
In this case, the aeon are configured, but no sources or groups accept been learned.
You can attending at one associate in added detail with the associate keyword:
Router#show ip msdp associate 192.168.201.15
MSDP Associate 192.168.201.15 (?), AS ?
Description:
Connection status:
State: Down, Resets: 0, Connection source: none configured
Uptime(Downtime): 00:13:28, Letters sent/received: 0/0
Achievement letters discarded: 0
Connection and counters austere 00:13:28 ago
SA Filtering:
Input (S,G) filter: none, route-map: none
Input RP filter: none, route-map: none
Achievement (S,G) filter: none, route-map: none
Achievement RP filter: none, route-map: none
SA-Requests:
Input filter: none
Sending SA-Requests to peer: disabled
Associate ttl threshold: 0
SAs abstruse from this peer: 0
Input chain size: 0, Achievement chain size: 0
And the arbitrary keyword shows accepted advice about all of the MSDP peers:
Router#show ip msdp summary
MSDP Associate Cachet Summary
Peer Abode AS State Uptime/ Reset SA Associate Name
Downtime Calculation Count
192.168.199.15 65531 Bottomward 00:15:41 0 0 ?
192.168.201.15 ? Bottomward 00:15:30 0 0 ?
Router#
The aftermost adaptation shows a analytical allotment of information. These MSDP aeon are currently unreachable, so no acquisition advice is actuality exchanged. In this case, the aeon accept been bottomward for over 15 minutes, acceptance you to abstract absolutely back the botheration occurred.
The aftermost two commands appearance capacity on the absolute multicast trees. The first, appearance ip rpf, shows advice about how the router would body an RPF timberline for a defined source. Note that this does not absolutely crave that this antecedent charge exist, or that it be currently sending multicast packets. It does crave that the interface that leads to this antecedent charge be configured for multicast forwarding, however:
Router#show ip rpf 192.168.3.2
RPF advice for ? (192.168.3.2)
RPF interface: Ethernet0
RPF neighbor: ? (192.168.5.1)
RPF route/mask: 192.168.3.0/255.255.255.0
RPF type: unicast
Router#
If there are two or added according amount paths to the aforementioned destination, the router artlessly selects the one with the accomplished IP address:
Router#show ip avenue 192.168.4.29
Routing admission for 192.168.4.28/30
Accepted via "eigrp 65530", ambit 90, metric 297372416, blazon internal
Redistributing via eigrp 65530
Aftermost amend from 192.168.4.26 on Tunnel6, 00:07:25 ago
Acquisition Descriptor Blocks:
* 192.168.4.22, from 192.168.4.22, 00:07:25 ago, via Tunnel5
Avenue metric is 297372416, cartage allotment calculation is 1
Absolute adjournment is 505000 microseconds, minimum bandwidth is 9 Kbit
Reliability 255/255, minimum MTU 1514 bytes
Loading 1/255, Hops 1
192.168.4.26, from 192.168.4.26, 00:07:25 ago, via Tunnel6
Avenue metric is 297372416, cartage allotment calculation is 1
Absolute adjournment is 505000 microseconds, minimum bandwidth is 9 Kbit
Reliability 255/255, minimum MTU 1514 bytes
Loading 1/255, Hops 1
Router#show ip rpf 192.168.4.29
RPF advice for ? (192.168.4.29)
RPF interface: Tunnel6
RPF neighbor: ? (192.168.4.26)
RPF route/mask: 192.168.4.28/255.255.255.252
RPF type: unicast
Router#
This is accessible back debugging multicast acquisition issues because it tells you, for example, that this avenue uses the unicast acquisition table. If you had advised for this acquisition advice to appear from some added antecedent such as DVMRP or MBGP, it tells you that there is apparently an Administrative Ambit problem. Here is how the achievement looks for addition antecedent that has a changeless multicast route:
Router#show ip rpf 192.168.55.5
RPF advice for ? (192.168.55.5)
RPF interface: Serial0
RPF neighbor: ? (192.168.254.6)
RPF route/mask: 192.168.55.5/255.255.255.0
RPF type: changeless mroute
Router#
For archetype the multicast copse for absolute sources, you can use the mstat command to get abundant added detail:
Router>mstat 192.168.3.2 239.5.5.55
Type escape arrangement to abort.
Mtrace from 192.168.3.2 to 192.168.5.2 via accumulation 239.5.5.55
From antecedent (?) to destination (?)
Waiting to accrue statistics......
Results afterwards 10 seconds:
Antecedent Acknowledgment Dest Packet Statistics For Alone For Traffic
192.168.3.2 192.168.5.2 All Multicast Cartage From 192.168.3.2
| _ _/ rtt 7 ms Lost/Sent = Pct Amount To 239.5.5.55
v / hop 7 ms --------------------- --------------------
192.168.3.1
192.168.5.1 ?
| ^ ttl 0
v | hop 0 ms -2/0 = --% 0 pps 0/0 = --% 0 pps
192.168.5.2 ?
| \\_ _ ttl 1
v \\ hop 0 ms 0 0 pps 0 0 pps
192.168.5.2 192.168.5.2
Receiver Concern Source
Router>
This command tells the router to absolutely delving the RPF timberline by appliance a agnate abode to that acclimated by the traceroute program. It presents the after-effects starting at the top with the antecedent and archetype bottomward to the receiver, which is the router itself, at the bottom, and shows all of the average router hops. There is a lot of advantageous advice in this output. It tells you, for example, the minimum antecedent TTL amount appropriate to ability anniversary point in the network. And it additionally shows the multicast forwarding packet statistics at anniversary hop for both this accumulation and for all multicast traffic. You can use this to actuate if you are accident multicast cartage due to bottleneck at some point in your network.
Here is addition absorbing mstat achievement in which the router discovers a TTL boundary:
Router#mstat 192.168.1.201 239.5.5.55
Type escape arrangement to abort.
Mtrace from 192.168.1.201 to 192.168.254.5 via accumulation 239.5.5.55
From antecedent (?) to destination (?)
Waiting to accrue statistics......
Results afterwards 10 seconds:
Antecedent Acknowledgment Dest Packet Statistics For Alone For Traffic
0.0.0.0 192.168.254.5 All Multicast Cartage From 192.168.1.201
| _ _/ rtt 3 ms Lost/Sent = Pct Amount To 239.5.5.55
v / hop 3 ms --------------------- -----------------
0.0.0.0
192.168.254.6 ? Hit ambit boundary
| ^ ttl 64
v | hop 0 ms -2/0 = --% 0 pps 0/0 = --% 0 pps
192.168.254.5 ?
| \\_ _ ttl 65
v \\ hop 0 ms 0 0 pps 0 0 pps
192.168.254.5 192.168.254.5
Receiver Concern Source
Router#
Notice that at the 192.168.254.6 hop, mstat discovers that there is a TTL abuttals with a beginning amount of 64. So you can see that the minimum TTL appropriate to ability the final destination is 65. This is an acutely advantageous command for isolating multicast acquisition problems