[c-nsp] Operational impact of switching from ingress to egress replication mode

[John Neiberger]

If I recall correctly, we have over 500 mroutes. I was just speaking
to a Cisco engineer that works with us about this. I think I'm going
to save this change until last. We have a lot of etherchannels and we
want to convert those to routed links with ECMP first, then we'll
switch over to egress replication. It sounds like we shouldn't have
more than a couple of seconds of impact.

Thanks!
John

On Tue, Sep 21, 2010 at 12:46 PM, Tim Stevenson <tstevens at cisco.com> wrote:
> Hi John,
> Switching replication modes basically purges the hardware of all mroutes and
> those will be reprogrammed based on the current software state. It will be
> potentially disruptive for all mroutes, but the exact amount of traffic
> loss/blackholing would depend on the rate of each stream at the time, and
> the overall amount of time it takes to reprogram. For a few 100 mroutes, I
> would not expect much impact.
>
> Hope that helps,
> Tim
>
> At 11:30 AM 9/21/2010, John Neiberger averred:
>
>> We're running 12.2(33)SRC2, I believe. It's actually experimental code
>> and the exact version is overwritten with another code.
>>
>> On Tue, Sep 21, 2010 at 12:04 PM, Jeffrey Pazahanick <jeffpaz at gmail.com>
>> wrote:
>> > John,
>> > Having switched back and forth a few times, I never noticed more than
>> > a 1-2 second outage.
>> > What version of code are you on?
>> >
>> > On Tue, Sep 21, 2010 at 11:59 AM, John Neiberger <jneiberger at gmail.com>
>> > wrote:
>> >> We're going to be doing a whole bunch of maintenance tonight during a
>> >> maintenance window. One of the many things on our plate is to switch
>> >> from ingress replication mode to egress on some 7600s that have a few
>> >> hundred multicast routes on them. We know there is going to be at
>> >> least a minor blip while things settle down after making the change,
>> >> but I wanted to see if anyone on the list has done this and what the
>> >> operational impact was. I've heard there will be slight interruption
>> >> in traffic, but what sort of interruption are we talking about? Are we
>> >> speaking about a second or two?
>> >>
>> >> I'm asking because we're trying to decide if we want to split this out
>> >> to another night. If the disruption is minor and the risk is low then
>> >> we'll do it tonight. Otherwise, we might choose to do it on a separate
>> >> night.
>> >>
>> >> Any thoughts?
>> >> _______________________________________________
>> >> cisco-nsp mailing list  cisco-nsp at puck.nether.net
>> >>
>> >> <https://puck.nether.net/mailman/listinfo/cisco-nsp>https://puck.nether.net/mailman/listinfo/cisco-nsp
>> >> archive at
>> >> <http://puck.nether.net/pipermail/cisco-nsp/>http://puck.nether.net/pipermail/cisco-nsp/
>> >>
>> >
>>
>> _______________________________________________
>> cisco-nsp mailing list  cisco-nsp at puck.nether.net
>>
>> <https://puck.nether.net/mailman/listinfo/cisco-nsp>https://puck.nether.net/mailman/listinfo/cisco-nsp
>> archive at
>> <http://puck.nether.net/pipermail/cisco-nsp/>http://puck.nether.net/pipermail/cisco-nsp/
>
>
>
>
> Tim Stevenson, tstevens at cisco.com
> Routing & Switching CCIE #5561
> Distinguished Technical Marketing Engineer, Cisco Nexus 7000
> Cisco - http://www.cisco.com
> IP Phone: 408-526-6759
> ********************************************************
> The contents of this message may be *Cisco Confidential*
> and are intended for the specified recipients only.
>
>
>