Can no longer access the internet on Cisco 2900

[jnix]

After a powerloss last night one of my networks can no longer access the internet.

The router (Cisco 2901) is configured, and can access the internet, but the server and all the workstations can't ping the gateway.

The network is on a 192.168.4.0 subnet, with the router interface at 192.168.4.1. The server is 4.200 and all the workstations receive dhcp from the server.

The router receives dhcp from the ISP (we're getting static but it hasn't happened yet.)

Everything inside the network works fine, but I can't figure out what is going on when trying to get outside.

[Daniel Mckibbin · Accepted solution]

The only thing I can see is that interface Gig 0/1 does not have an ip address. If this interface is to receive an ip address from your ISP as stated in your post, issue the command ip address dhcp:

Old:

interface GigabitEthernet0/1
no ip address
ip nat outside
ip virtual-reassembly
duplex auto
speed auto

New:

interface GigabitEthernet0/1
ip address dhcp
  ip nat outside
  ip virtual-reassembly
  duplex auto
  speed auto

Based on what I can see with the configuration, is that addresses matching acl 10 are to use Gig 0/1 for translation; however no ip address is assigned to this interface. Possibly this command was entered previously and the memory was not written to.

Cheers,

Daniel

[Mathias Garcia]

I agree with Daniel.

The one thing im a bit confused about is that you mention that the router can reach Internet?

If so over what interface/vlan? Since your running eigrp is it possible your getting a default route from some other router in your network?

Btw: you mention that servers and workstations cant ping the gateway. Do you mean the 2901 on 192.168.4.1 or an ip in the ISP network?

If they cant ping the 4.1 address you probably lost vlan 2 from a trunk somewhere.

[jnix]

Thanks for your help everybody.

I fixed the problem myself.  The problem was the switch's configuration got corrupted, or at least part of the configuration did.  One of the ports was no longer acting as a trunk and that's why none of the workstations could ping the router, but the router could ping the internet.

Again, thanks for your help.