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IP multicast is broken

I'm using some multicast tools referred to in the document "Cisco - Basic Multicast Troubleshooting Tools', to troubleshoot a multicast problem.

The source is 164.72.100.71

A receiver is 164.72.242.179

The RP is on the router at 164.72.187.142 shown in the output below as 'query source'.

My question for the output of the tool 'mstat'. I have to idea what it is telling me other than the path from source to receiver. The document does not explain how to use the output to find problems.

I think the multicast stream is breaking at the 4th hop (mroute counters don't increament on that router) which is 164.72.187.145 in the output below.

Does anything from the output tell you there is a problem?

ROC-RT7206-QMOE#mstat 164.72.100.71 164.72.242.179 239.192.10.1

Type escape sequence to abort.

Mtrace from 164.72.100.71 to 164.72.242.179 via group 239.192.10.1

From source (ROC2WG.GHC.ORG) to destination (?)

Waiting to accumulate statistics......

Results after 10 seconds:

Source Response Dest Packet Statistics For Only For Traffic

164.72.100.71 164.72.187.142 All Multicast Traffic From 164.72.100.71

| __/ rtt 12 ms Lost/Sent = Pct Rate To 239.192.10.1

v / hop 9 ms --------------------- --------------------

164.72.100.1

164.72.187.57 ?

| ^ ttl 0

v | hop -9 ms 15/35 = 43% 3 pps 17/35 = 49% 3 pps

164.72.187.58

164.72.187.10 ?

| ^ ttl 1

v | hop 0 ms 15/18 = 83% 1 pps 17/18 = 94% 1 pps

164.72.187.9

164.72.187.189 ?

| ^ ttl 2

v | hop 2 ms -19/1 = --% 0 pps -17/1 = --% 0 pps

164.72.187.190

164.72.187.145 ?

| ^ ttl 3

v | hop 0 ms 15/18 = 83% 1 pps 18/18 = 100% 1 pps

164.72.187.146

164.72.178.1 ?

| ^ ttl 4

v | hop 4 ms -3/0 = --% 0 pps 0/0 = --% 0 pps

164.72.178.2

164.72.245.5 ?

| ^ ttl 5

v | hop 1 ms -2/1 = --% 0 pps 0/0 = --% 0 pps

164.72.245.6 ?

| \__ ttl 6

v \ hop 2 ms 0 0 pps 0 0 pps

164.72.242.179 164.72.187.142

Receiver Query Source

Another question has to do with the output of 'mtrace', which is supposed to give me TTL thresholds and delays. As you can see from the output, there is no TTL threshold or delay fields. Any idea why?

ROC-RT7206-QMOE#mtrace 164.72.100.71 164.72.242.179 239.192.10.1

Type escape sequence to abort.

Mtrace from 164.72.100.71 to 164.72.242.179 via group 239.192.10.1

From source (ROC2WG.GHC.ORG) to destination (?)

Querying full reverse path...

0 164.72.242.179

-1 164.72.245.6 PIM [164.72.100.0/25]

-2 164.72.245.5 PIM [164.72.100.0/25]

-3 164.72.178.1 PIM [164.72.100.0/25]

-4 164.72.187.141 PIM Reached RP/Core [164.72.100.0/25]

-5 164.72.187.182 PIM [164.72.100.0/25]

-6 164.72.187.30 PIM [164.72.100.0/25]

-7 164.72.187.57 PIM [164.72.100.0/25]

ROC-RT7206-QMOE#

I've attached a text file for better reading of the outpus.

1 REPLY
Silver

Re: IP multicast is broken

Not all sites of a single unicast VRF must be configured for multicast. It is possible to have some sites (and even interfaces of MVPN PE router) where multicast is not enabled. You must ensure that routes are never calculated to point to non-multicast enabled interfaces. Otherwise, multicast forwarding will be broken

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