[j-nsp] Multicast flow with "Wrong incoming interface notifications" counter incrementing

[Nilesh Khambal]

Iif mismatch means the multicast traffic received for this (S,G) has a different incoming interface than the one we programmed in the PFE (based on RPF check). 

Traffic would get discarded in this case and not forwarded. However, a notification is sent to RPD/PIM on the RE to check if the we need to change the iif on this (S,G) to a new iif (for e.g. if this leads to RPT to SPT cutover or if there is a change in the iif due to RPF interface change)

If the counter increase consistently, then most likely you are not forwarding on that (S,G) if 100% of the incoming traffic on this (S,G) get discarded with iif mismatch. Alternately, you might be getting same (S,G) traffic on 2 different iifs and in this case one coming over correct iif gets forwarded and one over wrong iif gets discarded with iif mismatch counted against that (S,G).

Thanks,
Nilesh. 

--------------------------------
Sent from my mobile device

On Jan 14, 2013, at 8:14 AM, "Riccardo S" <dim0sal at hotmail.com> wrote:

> 
> 
> 
> Hi
> 
> What does means incrementing counter
> “Wrong incoming interface notifications” in the following command ?
> 
> Is the following flow forwarded, as expected,
> towards the receiver ?
> 
> 
> 
> 
> 
> # run show multicast route group
> 224.12.22.1 extensive    
> 
> Instance: master Family: INET
> 
> 
> 
> Group: 224.12.22.1
> 
> 
> Source: 1.1.1.1/32 
> 
> 
> Upstream interface: vlan.1
> 
> 
> Downstream interface list: 
> 
>        vlan.100
> 
> 
> Session description: Unknown
> 
> 
> Statistics: 3 kBps, 30 pps, 43340 packets
> 
> 
> Next-hop ID: 131071
> 
> 
> Upstream protocol: PIM
> 
> 
> Route state: Active
> 
> 
> Forwarding state: Forwarding
> 
> 
> Cache lifetime/timeout: 360 seconds
> 
> 
> Wrong incoming interface notifications: 6960
> 
> 
> Uptime: 00:36:36
> 
> 
> 
> After 10 seconds:
> 
> 
> 
> # run show multicast route group
> 224.12.22.1 extensive    
> 
> Instance: master Family: INET
> 
> 
> 
> Group: 224.12.22.1
> 
> 
> Source: 1.1.1.1/32 
> 
> 
> Upstream interface: vlan.1
> 
> 
> Downstream interface list: 
> 
>        vlan.100
> 
> 
> Session description: Unknown
> 
> 
> Statistics: 2 kBps, 30 pps, 43491 packets
> 
> 
> Next-hop ID: 131071
> 
> 
> Upstream protocol: PIM
> 
> 
> Route state: Active
> 
> 
> Forwarding state: Forwarding
> 
> 
> Cache lifetime/timeout: 360 seconds
> 
> 
> Wrong incoming interface notifications: 6974
> 
> 
> Uptime: 00:36:41
> Tks
> 
> 
>                         
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