No internet access from LAN

[elementaita]

Hi,

I'm kind of new to IOS and am having trouble configuring a 1721 router as an internet gateway. The router itself has access to the internet -- I can ping externaly hosts by both IP and name from the console. I also have access to the router from the internal lan -- I can telnet to the router and ping it from a host on the lan.

However, I do not have access to the internet from the lan. I can't ping any host on the internet from a machine on the lan, even by IP. I can ping the router's external interface (it's a T1 WIC), but nothing beyond that.

I'm using a very stripped down config to try and get this going:

access-list 1 permit 192.168.0.0 0.0.0.255

interface FastEthernet0
  ip address 192.168.0.1 255.255.255.0
  no shutdown
  ip access-group 1 in
exit

!x.x.x.x = my external IP
interface Serial0
  ip address x.x.x.x 255.255.255.252 
  no shutdown
  no fair-queue
  service-module t1 timeslots 1-24
  exit

ip name-server 4.2.2.1

ip route 0.0.0.0 0.0.0.0 serial0

Any help or suggestions much appreciated!

 

[KiscoKid]

I'm presuming your LAN hosts all have 192.168.0.x addresses? If so, the router (or firewall if you have one) will need to NAT (translate) these addresses to a public address. Try adding the following and see how that improves things:

interface FastEthernet0
ip nat inside

interface Serial0
ip nat outside

ip nat inside source list 1 interface serial0 overload

access-list 1 permit 192.168.0.0 0.0.0.255

 

[voltron1011]

Yeah, it looks like you're misssing your NAT configuration.

 

[elementaita]

Thanks KiscoKid. This did the job. It now works fine.