[c-nsp] Cisco 7600/SUP720-3BXL SRD -> SRE => Egress -> Ingress Multicast Replication Mode

[Emanuel Popa]

On Fri, Aug 3, 2012 at 4:05 PM, Phil Mayers <p.mayers at imperial.ac.uk> wrote:
> On 03/08/12 12:54, Emanuel Popa wrote:
>>
>> Hi there,
>>
>> A while ago we upgraded our 7600 Cisco boxes with SUP720-3BXL and LAN
>> cards from SRD to SRE IOS version. After successfully upgrading all
>
>
> Some features are incompatible with egress mode. It's possible that the IOS
> upgrade introduced more checks and/or forced ingress mode as problems were
> found
>
> For example, MVPN needs ingress mode, and IIRC QoS and SPAN have problems
> with egress mode.
>
>
>> boxes we noticed at least a strange behavior: all Cisco 7600 boxes had
>> "mls ip multicast replication-mode ingress" as an extra command in
>> their running configuration file. Before upgrading, all boxes were
>> doing egress replication for multicast traffic. And it seems they are
>
>
> Are you sure? You checked this with the "sh platform" command?

I'm pretty sure. We spent quite some time with our multicast setup in
the past to understand the difference between the P and the PE routers
when it comes to MVPN. Because of the ingress replication mode on the
PE routers we installed dedicated PE routers for the MVPN traffic.
This way we manged to keep egress replication mode on every other
router in the network.

>> still able to do it:
>>
>> #show platform software multicast ip capability
>
>
> What happens if you "no" the command and let it go back to auto-detect mode?

When you "no" that command the router simply moves from auto-detection
OFF to auto-detection ON and replication mode switches from ingress to
egress.