IPMC log messages recommendation steps

  • 0
  • 1
  • Question
  • Updated 4 years ago
  • Doesn't Need an Answer
  • (Edited)
09/18/2014 11:21:31.53 Slot-1:
Unable to set IPMC index for s,G,v=ac13b243,effffffa,233 IPMC 8, unit 0 Invalid
parameter

09/18/2014 11:21:31.53 Slot-1: Bcm
not found SetBCM IPMC index for s,G,v=ac13b243,effffffa,233 IPMC 8, unit 0
00000000 00000000

09/18/2014 11:21:31.53 Slot-1:
Unable to set IPMC index for s,G,v=ac13b242,effffffa,233 IPMC 8, unit 0 Invalid
parameter

 

 

Such errors are frequently logged for multiple customers
when IGMP & IPMC compressions are enabled by default which is not a  hardware issue.

 

This logs are due to IPMC hardware entries which cannot be
seen through the normal CLI.

 

The same can be cleared on following below recommendation,

 

1.            disable
igmp snooping - - -> By default enabled – this command disables igmp
snooping.

2.           
configure forwarding ipmc compression off - -- > By default enabled –
to reduce IPMC entries – this command disables compression

3.           
configure igmp snooping filters per-vlan 
- - -- reduces igmp entry – by default it was per-port – which will
have more IPMC entries

4.           
configure igmp snooping forwarding-mode group-vlan - - -> reduces
igmp entry – by default it was source,group,vlan – which will have more IPMC
entries

5.           
configure forwarding ipmc compression group-table - -  enable back
compression to reduce IPMC entries

6.            enable
igmp snooping - - -> enabling back igmp snooping

 

Steps 3 to 5 to have reduced IPMC entries.

 

The reason these messages are seen in the switch
is due to lots of clearing and re-learning of group table entries events
happening which results in few entries failing to get re-learnt. At this stage
we see those IPMC related errors. This is the situation where we see mismatch
of entries with software and hardware. 

In order to overcome the issue, turning off the
IPMC compression is the only solution. 

When IPMC Compression is turned off, switch will
not try to clear all the entries and re-learn instead it clears only the
particular group table entry and will not impact other existing S,G,V entries. 

Now a little on the IP multicast compression . 

IP multicast compression provides additional IP
multicast scaling when multiple IP multicast FDB entries have the same egress
subscriber list. 
Photo of Sumit Tokle

Sumit Tokle, Alum

  • 5,738 Points 5k badge 2x thumb

Posted 4 years ago

  • 0
  • 1
Photo of PARTHIBAN CHINNAYA

PARTHIBAN CHINNAYA, Alum

  • 4,362 Points 4k badge 2x thumb
There are much better options available in 15.x
Latest versions. Best one is upgrade code which will have multicast control packets flood in hardware .(fast path)