Problem with Internet Connectivity on 871W router

pavanbabut · ‎02-19-2009

I am trying to setup a 871W router to work as a wireless LAN in our lab. I would like to connect it to a shared internet port on our server for internet access (WAN port). I can ping router from the system thats connected to the router LAN (FE0) and I can also ping to the gateway (shared port) too. But I was not able to ping anything else outside that. No internet connectivity either.. This is the first time I am configuring a cisco router, it would be great if you can guide me in right direction.

thanks

Giuseppe Larosa · ‎02-19-2009

Hello Pavan,

the following link can help

http://www.cisco.com/en/US/docs/routers/access/800/850/software/configuration/guide/wireless.html

what you need:

a default static route on the 871W pointing to the gateway port.

the internet gateway needs a route to the subnet that the 871W uses for the wireless lan

then because we use private ip addresses inside all networks someone has to do NAT:

or the internet gateway is configured for NAT of the wireless lan subnet or:

the 871W has to NAT the wireless lan ip subnet using its ip address on the wired link.

for NAT commands on the 871W look the following

http://www.cisco.com/en/US/docs/routers/access/800/850/software/configuration/guide/pppoenat.html#wpxref20820

you need

ip nat inside on the correct layer 3 radio interface

bvi 1 associated to vlan 1 = dot1q 1

int bvi1

ip nat inside

ip nat outside on ethernet towards gateway

access-list 10 permit 10.10.10.10 0.0.0.255

ip nat inside source list 10 inter fas0/0 overload

the gateway has to then NAT to be able to access the internet

Hope to help

Giuseppe

pavanbabut · ‎02-24-2009

I am attaching my config file.. is there something I need to change... I still cant access internet on my system connected to FE0. The WAN connection is the shared connection using a static IP.

Giuseppe Larosa · ‎02-25-2009

Hello Pavan,

you should check the state of interface vlan1 and bv1

if you feel confident with telnet access

do

sh ip int brief

check if they are up/up

you may need to enable them with

conf t

int vlan 1

no shut

int bv1

no shut

2) does the PC connected to lan interface fas0 receive an ip address from the pool

you can check it from the shell

with ipconfig /all

on the router you can verify if NAT is working with

sh ip nat translations

3) to be noted I think you should a radio11 subinterface as in the example I linked from config guide

Hope to help

Giuseppe

pavanbabut · ‎04-15-2009

Sorry I didn't reply for a long time. I was able to get it running by using a excel worksheet provided on TechRepublic, with minor additions to make it work for mine.

thanks for your help.