[c-nsp] Setting relay agent IP on 4500

[Jason Lixfeld]

Hi all,

I’ve got a 4500 Sup7L-E running 15.2(2) acting as a DHCP relay with clients directly connected to it.  The client interfaces on this relay are in VRFs, and the helper is in the global table.

The issue is the 4500 stamps the relay agent IP in the DISCOVER as being the incoming interface IP where the DISCOVER was received, which is in a VRF.  As such, the DHCP server tries to send the OFFER to that IP, but it’s not reachable due to it being in a VRF, and is subsequently dropped upstream.

On ME3600s for example, ip dhcp-relay information option server-override resolves this, but I can’t seem to find this command on the 4500 leading me to believe that the same command isn’t supported.  I’m hoping there’s something similar that I just haven’t been able to find, but the command reference guides are pretty useless and I’ve come up empty so far.

Thanks!