I've just taken over a small business network with 2 Windows servers. SRV2 (Server 2008 R2) is primarily a data backup for SRV1 (Server 2003); they're both DNS servers as well.
Our primary LAN addresses are 10.x.x.x. The servers are also directly linked by Ethernet crossover cables, 2 NICs teamed to produce a 2Gbps connection; these connections are assigned 192.168.x.x addresses. The crosslink is for backup purposes; naturally I want LAN access to the servers to be by the 10.x.x.x addresses. That's worked fine up to today.
But this morning I replaced one of the two crossover cables between the servers, because I discovered it had two wires swapped. When I took over, the crosslink was barely active, and showed a speed of 1.1Gbps. With a new cable the link speed jumped to 2Gbps and became substantially more active.
The problem is: Now any DNS lookup of SRV2 returns the 192.x address instead of the 10.x address.
I've deleted the A records for SRV2 from both servers; they get recreated for 192.x, but not for 10.x. "Register this connection's addresses in DNS" is unchecked for the 192.x interface, checked for the 10.x interface. Nonetheless the 192.x address is what keeps showing up in the forward lookup tables.
What should I do to ensure that DNS serves the 10.x address for SRV2 instead of the 192.x address?
Updates: 1) SRV2 ran a backup of SRV1 last night; it looks like most (maybe all) of the traffic went across the 1Gbps 10.x interface.
2) I manually added A records for SRV2's 10.x address to both servers; they disappeared overnight. I suppose I should have set time-to-live on the Win2003 server, but that wasn't an option on the Win2008 server.
netstat -no shows no connections between the servers on the 10.x interfaces, only on 192.x.
4) I found this question: Windows DNS keeps re-registering deleted ip addresses which seems related, so I checked where my DNS servers were listening. SRV1 is listening on all interfaces - no surprise. But SRV2 doesn't even show the 10.x interface in DNS server properties; it only has the 192.x interface (and the associated link-local IPv6 address).