[f-nsp] ServerIron DSR source MAC address?

[Chris Woodfield]

Hi,

Does anyone know if there's a knob in TrafficWorks code to configure the source MAC address on packets that the SI forwards to a real server? I'm seeing a situation with a DSR VIP with the following chain of events:

- Port participating in STP flaps on the upstream switch, triggering a TCN and fast-aging of the switch's MAC table...
- The CAM entry for the configured VIP MAC address (this is in a backup pair config) ages out since DSR replies come from the real servers' MAC addresses, not the ServerIron's...
- Traffic to VIP IPs floods out all ports until a packet gets generated with the VIP's MAC address (generally in response to an ARP - I force this by clearing ARP on the upstream router).

I've noticed that the SI uses the burned-in chassis MAC address as its source when it forwards the packet to the real - what I'd really like to be able to do is change this to the same MAC I have configured in my "server backup" statements, so that packets with this source MAC come back into the switch and prevent the CAM aging.

Is this possible? Anyone else run into this and have a different solution?

Thanks,

-Chris