I set up some new vlans to improve security on my gigantic flat network. We have rental offices on site on the same network as our servers! Not good. I’ve decided to use 192.168 networks (10 total) in .25 increments (192.168.25.X, 192.168.50.X, etc). I was in the testing phase working with ACLs when I discovered some computers not being able to access computers on different subnets even though they can access others on that subnet. Example, I can successfully ping from 192.168.175.130 to 192.168.25.21. I cannot ping from 192.168.175.130 to 192.168.25.38. I can ping the 192.168.25.38 from anything on the 192.168.25.X network. I have a Cisco 2800 router and turned off the ACLs, problem still persists. I thought maybe it was the no proxy-arp command that was causing the intermittent issues but I turned on proxy-arp and that did not fix it either.
FYI: All subnets do have internet access – All subnets are physically connected to 1 interface with sub-interfaces in use (fa0/0.25, etc) – the ip addresses I’m having trouble with are not accessible from any of the new subnets (.14, .15, .16, .18, ,28 .38 to name a few) but other close numbers are (.7 , .10, .21, .37, etc). These nodes are all connected to the same switch.
I’m stuck on this one, has anyone had similar issues with a cisco 2800 series router?