Up until a few days ago we were able to telnet into the management IP of this switch. Now we can only do that on the subnet that its on. From the switch management console we can only ping IPs that are on the local subnet. To our knowledge no one has made any changes to the configuration of this switch. When trying to ping by host name, it resolves to the correct IP, but still can't ping it. Anyone have an idea of what might have happened and how to correct it?
It sounds like the default gateway for the switch is either not configured or not accurate. In the switch, enter "show ip route" and see if the default route is pointed to the correct gateway. If it is incorrect, enter the command "set ip route 0.0.0.0/0.0.0.0 (default gateway address)".
That is what I was thinking. For the router blade in the catalyst the gateway is 172.16.1.42, the ip for the switch is 172.16.1.41. When we do a show ip route it displays: 172.16.0.0 172.16.1.41. I tried to change it by using the clear ip route and then setting it to: 172.16.0.0 172.16.1.42 and when I hit enter it says that the route already exists. When I would do another show ip route, it still displays 172.16.1.41 as the gateway.
The route you are seeing is correct. The router is connected to 172.16.0.0 so its own interface 172.16.1.41 is the next hop to that network. That is what it is using to reach the local network.
What you are missing is the default route 0.0.0.0 172.16.1.42. Maybe its there but you did not mention it. The other option is that you are running a routing protocol so you dont need the default. Are you? Some how you need more routes than the one you mentioned.
Finally, you may have the route you need but might have an invalid arp entry on one side or the other. Did either host get changed so it has a different mac address on that interface? Can the 41 host ping the 42 host? Clear arp tables on both sides.
It appears that our gateway of last resort somehow got deleted. I did the set ip route 0.0.0.0 x.x.x.x (gateway) and we are now able to ping it and telnet into it from any subnet. Thanks to all who replied.
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