[j-nsp] MX960 ARP issues

[John Neiberger]

>
> I'd suggest looking at a couple of things...
>
> First, the arp cache cache timers on both the switch & routers.
> From memory, Cisco & juniper differed in when the arp cache was expired.
>
> On the router side, it'd be worth checking if accept-data is enabled at the
> interface level.
> Turning on passive learning may also be worth considering
> http://www.juniper.net/techpubs/en_US/junos12.3/topics/task/configuration/arp-learning-aging-options-configuring.html
>
> Cheers,
> Gordon
>

We do have accept data configured. I have to admit that even after
reading the docs just now, I'm not really sure I understand what it's
doing. It is standard in our templates, though, so every interface
running VRRP has accept data configured.

Passive learning is an interesting thought, but I'd still like to find
the root cause of the problem: why don't the IP addresses respond to
ARP requests from only this router? I'm nearly certain it's a server
issue but I haven't encountered anything quite like this before.

Thanks!
John