Puzzling intra-office network connectivity issue

Factual Questions
1

Argh, my long winded post got eaten :frowning: Ok, here goes again.

We’ve recently expanded our office across the hall. The network config is as follows.

South office - Most of the PCs, plus the firewall and T1. All PCs are connected to Netgear FS750Ts, which are connected via gigabit ethernet to a Linksys SRW2016. The firewall is also connected to the Linksys.

North office - a few PCs, plus the servers. The PCs are connected to a Netgear FS750T, which is connected to another Linksys SRW2016. The servers are connected to the Linksys via gigabit ethernet.

The two offices are connected via gigabit ethernet between the two Linksys SRW2016s.

Here’s the rub: Occasionally, communication from the South to the North fails (as determined with a simple ping), but the servers can still get to the firewall. Also, sometimes the southerners cannot ping the firewall, but can still get to the servers, and the servers can STILL get to the firewall.

Any ideas? I’m thinking of swapping out the south Linksys with a spare, but any suggestions are appreciated. I can get additionally configuration if needed, or draw up a quick diag.

Thanks!

2

Maybe the cable connecting the two offices is too long. If the cable is more than 300 feet long you need to use a switch or a bridge somwhere in the middle of the cable run.

3

Yeah, I had thought that. It’s only around 100 feet, and reports full duplex gigabit. Besides, the north office can transmit to the south, just not the other way around. :confused:

I’m pondering joining two ports into one to allow for 2gigabit traffic.

4

Are the IP addresses set up properly, no conflicts with subnets or DHCP? Is there a server involved here acting as a domain name controller? Is there more than one? Multiple domain controllers don’t play together well without extra configuration. But I’d make sure IP addresses are handed out properly as a first step, with all these routers and, apparently, active servers this might be a problem.

5

Single DHCP server, two AD domain controllers and other member servers. The servers, printers, firewall and WAPs have static IPs, everyone else is dynamically assigned.

I haven’t yet seen another device with the same IP as the firewall, but that’s something to look for.