Problem with multihomed PC, any ideas?

JayrodEF

I've got a PC at work that's got two NICs. One is assigned a static 10.10.10.x address that just connects to a server running an application on that subnet. The second NIC is usually disable becuase we're not using it right now. We'd like to enable it to be able to access things on the 192.168.1.x subnet which is what everything else is on. Problem is, when we enable the second NIC, the programs running on the machine run reallly slow. I don't see how just enabling the second NIC is causing performance problems for applications on the client. Any ideas would be great! It's a windows XP machine if that helps. I'm also not sure why we just don't put the 10.x server on the 192.x subnet and just use one NIC. We're trying to do it this way though.

Mishra

It sounds like a configuration mishap. Maybe you put gateways on both NICs?

The best test you could do is to run a traffic analyzer, try to run both NICs, and also try to run the NIC connected to the 192.168.1.0 subnet and have the 10.10.10 NIC turned off. You might have bad drivers on that NIC or a crazy amount of traffic on your 10.10.10 subnet.

hypnotoad

What kind of apps is it running?

I usually have to specify a default gateway on one NIC and a static route on the other, so it knows where the 192.168 network is.

taktsoi

Do not forget about the NIC binding order as well.

JayrodEF

Yeah, checked the binding order and such, looked fine to me. I ended up just setting the 192.x NIC up with a static IP, no default gateway or DNS. Disable the file and print sharing service and the QOS packet scheduler and things seem to be working fine. I only connect to one server by IP address anyway, so I don't really care about DNS or browsing the network or anything.

Luckycharms

1. XP running slow.
Q. Did you look at load from processes?
Q. Did you look at you network load on the XP computer? (pretty sure that some process was trying to get to some gateway and you didn't have a preferred GW so it got pretty pissed off. Yes, you probably had you DG configured for the two Nic's but the OS still need to know which one is the preferred DG.

Routing
2. You need to read on Route weighting, XP doesn't like having 2 nics on two different subnets with out some kinda of route weighting. ( to be honest most thing don't)
The weighting for XP is under TCP/IP settings. Click Advanced and then look at the Automatic metric. Un-check that and then give what ever interface you want the lower number. (anything less then 255) This should fix most of your problems. Good luck