[c-nsp] Setting CS0 on ARP traffic

[Tony]

On Thu, 29 May 2014 22:03:22 +1000, Tom Hill <tom at ninjabadger.net> wrote:

> On 29/05/14 12:20, Tony wrote:
>> Both of these are sub-optimal solutions, so obviously we'd like to
>> find a way to set the outbound traffic from the ES20 card to CS0 so
>> that it can work how we expected it to.
>>
>> Any suggestions appreciated.
>
> Static ARP entries? If the carrier is providing your gateway via  
> VRRP/HSRP, it might be somewhat less painful through upgrades.

Carrier is providing a L2 service, we've got a /30 over it with 7609 on  
one end and 1841 (for testing) at the CPE end.

It does work with static ARP entries, we tested this, but we'd prefer not  
go this route if possible (messy), also means that if we try to run other  
stuff that has issues with setting CoS on (eg. something like OSPF  
perhaps) will have same problems. It isn't JUST an issue with ARP's, that  
is just the most obvious manifestation in trying to get the service  
working.

>
> Does the 7600 supervisor that you're using support egress CoPP, to  
> fettle the ARP entries there (rather than on the egress port)? I must  
> admit, I've never tried it.
>

It's a SUP720-3B, not sure. Also not sure whether the ARP response comes  
 from the SUP or the ES20 card itself ? It's worth investigating a little  
though, thanks. Only problem I can see is that this is a production box  
with hundreds of other services on it, so I need to be careful of causing  
any other problems when messing with CoPP.


Thanks,
Tony.