I am facing the same issue.
Recently 1 more NIC was added to one of our SAN Media server and from that time the backups starts giving error.
I made the host entry of both Ip address and the issue not fixed. I cleaned the cache but no luck.
Can you please provide the step by step configuration to resolve the issue. The NSLOOKUP of the SAN Media server resolves both the ip address.
When i ping and bptestbpcd from the master it takes first ip and when i execute the same from media server it points the second ip.
check these technotes and use the Preferred Network setting.
or use route command to configure the gateway that connect the media server to the master