Switch can't ping outside local subnet

[Colin Higgins]

I recently installed a 3750 (24 port) into my network and trunked it (dot1q) to a stack of existing 3750s.

The VTP settings seem correct: the new switch is getting the vlans across the trunk and the revision number looks good.

Interface Vlan1 is assigned an ip address and it can ping resources on its local subnet. There is a default gateway set on the new switch, and it can ping the gateway.

However, the new switch cannot ping outside its subnet, and devices in other subnets cannot ping it (or telnet).

Anyone have any idea what might be the problem here?

[Jon Marshall]

I know this sounds like a stupid question but are you sure the default-gateway is the correct one ?

If you are, from the new switch can you ping any of the other L3 vlan IP addresses on the switch that has the default-gateway ?

Jon

[Colin Higgins]

Yep, default gateway is correct, and the switch can ping it.

No access lists are between the switch and the resources outside the local subnet I am trying to ping

[Jon Marshall]

The new switch, is it acting as L2 only ie. you have not configured "ip routing" on it ?

The default-gateway for vlan 1 - is that on the switch stack ? If so there are probably other L3 vlan interfaces for other vlans. Can you try pinging one of those L3 vlan interfaces from your new switch.

Jon

[Colin Higgins]

ip routing is enabled on the new switch

the default-gateway is the switch stack that runs EIGRP (and has a default route configured on it).

the switch stack has 7 other subnets (vlans) configured on it. I cannot ping any of them from the new switch.

[Jon Marshall · Accepted solution]

colin-higgins wrote:
ip routing is enabled on the new switch
the default-gateway is the switch stack that runs EIGRP (and has a default route configured on it).
the switch stack has 7 other subnets (vlans) configured on it. I cannot ping any of them from the new switch.

Is the new switch meant to be routing anything ? If it is then use a default-route instead of a default-gateway or alternatively run EIGRP between the new switch and the switch stack.

If it is not meant to be routing then turn off routing and then the default-gateway configured on the new switch will be used.

Jon

[Colin Higgins]

that was the problem Jon

thanks!

Since ip routing was turned on, it was ignoring the default statement. When I put in an "ip route 0.0.0.0 ..." statement, everything worked.

[Jon Marshall]

Colin

No problem, glad to have helped.

Just for your info. If the new switch is not doing any inter-vlan routing ie. all the vlans are routed off the switch stack then it is common practice to simply not enable "ip routing" and just use the default-gateway.

Jon

[Freihafener]

In addition to jons suggestions: are the subnet masks on all devices involved correct?