Multi-honed, PDC, Explore access weirdness

[WillShakespeare]

Sorry for the strange title, but I don't know what's happeneing exactly, I can only describe the symptoms and my thoughts so far. I would really appreciate some quick help on this.

I have 4 servers:
A B C D

A and C are Windows 2003 Domain Controllers. B is an exchange server, and D is a backup server with BackupExec.

The BackupExec keeps failing to backup A and C. I now know this is not a BackupExec problem, that's why I'm here.

Anyway, each server has 2 NICs. The network settings for each is thus:

NIC # 1, our network:
10.19.70.#
255.255.255.0
10.19.70.4

NIC # 2, a separate GB switch network for backups:
10.10.70.#
255.255.255.0
N/A

So, if I access B from D by clicking Start -> Run: \\10.10.70.2

Explorer opens up immediately for that server.

If I try to do the same to access either A or C, no window pops up, and after a timeout I get an error that I do not have permissions to access that server.

However, for any of the 4 servers if I do the same but with the normal network IP, all works fine.

hmmm... now that Ihave this down I am beginning to wonder... Might this be because of a domain permissions issue? The normal domain IP is fine because that is our domain. But the new GB Switch network is NOT a domain as such. Maybe that's the cause!

If so, can anyone help me alter settings to make it possible to do this? Or at least confirm I can't?

Alternatively, have you got any ideas of your own?

Thanks in advance,

Will

 

[WillShakespeare]

Forgot to mention, when I first tested the GB idea for backups, I had a crossover cable between server D and server A. And the same IP info above.

The network over rthis link worked fine. It is only since I started using the switch that it has stopped working.

Will

 

[WillShakespeare]

Oh and one other thing:

I can ping from all servers both IP addresses. I can ping -a, and get back appropriate names.

If I do the Start -> Run: \\10.10.70.4

from server A (to server D) Explorer pops up fine. It is only if I try it from server D to access A or C that is the problem.

Again thanks in advance...

 

[itsp1965]

Being that is is a multi-homed server you should disable all MS related services on the NIC pointing to the backups subnet. You are probably experiencing network browsing issues which is causing the issues are experiencing
Also make sure that the IP address for the NIC pointing to the backup subnet does not appear in DNS/WINS as associated to the host.
Hope this helps

 

[WillShakespeare]

That sounds along similar lines to my thinking. The problem is that when I change the NIC settings, a warning ops up to say I haven't set a DNS server, and so because the local server is a DNS server, it will use it instead. There is no operation to override this.

So anyway, the DNS entries happen by default. I wonder if an entry in the hosts file would help?

 

[WillShakespeare]

Funny... I removed the check box that auto adds the DNS entires, and then deleted the entries in the DNS server.

Voila! Now I can do the Start -> Run thingy!

But the BackupExec still fails...

Bum!!

 

[itsp1965]

Did you try clearing your NetBIOS cache (nbtstat -RR) and DNS cache (ipconfig /flushdns). Also under the WINS tab of the backup netowrk interface ensure you have disabled NetBIOS over TCPIP

 

[WillShakespeare]

Are you sure about disabling NetBIOS? The description of NetBIOS in the WINS window does suggest enabling it in such situations.

I'll give it a try and let you know, however.