Hi have you tried

brcruz001 · ‎01-16-2016

Hi there,

This is my first time playing with a Router. I have a Cisco 2901, and despite the many different topics and how-to's available here and in other places, I still can't get internet access to my computer behind the router. I have a modem (provided by my ISP) connected to my router's GE0/0 port, and a computer connected on interface GE 0/1. What have I accomplished so far:

- Router is getting an DHCP IP from ISP;

- Router can ping computer, and computer can ping router. From my computer I can even ping Router's GE0/0/;

- Router can ping internet resources, computer behind it cannot;

Here's my show-run-config:

C2901#show running-config
Building configuration...

Current configuration : 1531 bytes
!
! Last configuration change at 21:37:52 UTC Sat Jan 16 2016
!
version 15.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname C2901
!
boot-start-marker
boot-end-marker
!
!
enable secret 5 XXXXXXXXXXXXXXXXXXXXX.
enable password XXXXXXX
!
no aaa new-model
!
!
no ipv6 cef
ip source-route
no ip routing
no ip cef
!
!
!
!
!
ip name-server 201.17.0.79
!
multilink bundle-name authenticated
!
!
!
!
!
crypto pki token default removal timeout 0
!
!
voice-card 0
!
!
!
!
!
!
!
license udi pid CISCO2901/K9 sn FTX172885WN
hw-module pvdm 0/0
!
hw-module pvdm 0/1
!
!
!
!
redundancy
!
!
!
!
!
!
!
!
!
!
!
interface Loopback0
ip address 192.168.254.1 255.255.255.0
ip virtual-reassembly in
!
interface GigabitEthernet0/0
description INTERNET
ip address dhcp
ip nat outside
ip virtual-reassembly in
no ip route-cache
duplex auto
speed auto
!
interface GigabitEthernet0/1
description LAN
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
no ip route-cache
duplex auto
speed auto
no mop enabled
!
interface Virtual-Template1
ip unnumbered Loopback0
ip nat outside
ip virtual-reassembly in
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
!
!
!
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
gatekeeper
shutdown
!
banner exec ^CEntering EXEC mode on R2901...^C
!
line con 0
line aux 0
line vty 0 4
password XXXXXXXX
login
transport input all
!
scheduler allocate 20000 1000
ntp server 200.186.125.195
end

I know there area a few things missing (ACL's), but as my first step, I just want to connect to the internet.

Can anyone help?

brcruz001 · ‎01-17-2016

I made a few changes, but still no connectivity from my computer to the internet. Here's my updated build:

C2901#show running-config
Building configuration...

Current configuration : 1777 bytes
!
! Last configuration change at 12:30:21 UTC Sun Jan 17 2016
!
version 15.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname C2901
!
boot-start-marker
boot-end-marker
!
!
enable secret 5 XXXXXXXXXXXXXXXXXXXXXX
enable password XXXXXXXX
!
no aaa new-model
!
!
no ipv6 cef
ip source-route
no ip routing
no ip cef
!
!
!
!
!
ip name-server 201.17.0.79
!
multilink bundle-name authenticated
!
!
!
!
!
crypto pki token default removal timeout 0
!
!
voice-card 0
!
!
!
!
!
!
!
license udi pid CISCO2901/K9 sn FTX172885WN
hw-module pvdm 0/0
!
hw-module pvdm 0/1
!
!
!
!
redundancy
!
!
!
!
!
!
!
!
!
!
!
interface Loopback0
ip address 192.168.254.1 255.255.255.0
ip virtual-reassembly in
!
interface GigabitEthernet0/0
description INTERNET
ip address dhcp
ip nat outside
ip virtual-reassembly in
no ip route-cache
duplex auto
speed auto
!
interface GigabitEthernet0/1
description LAN
ip address 192.168.1.1 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat inside
ip virtual-reassembly in
no ip route-cache
duplex auto
speed auto
no cdp enable
no mop enabled
!
interface Virtual-Template1
ip unnumbered Loopback0
ip virtual-reassembly in
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip nat pool NATPOOL 192.168.0.11 192.168.0.11 prefix-length 24
ip nat inside source list 1 pool NATPOOL overload
ip route 0.0.0.0 0.0.0.0 192.168.0.1
!
access-list 1 permit 192.168.1.0 0.0.0.255
!
!
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
gatekeeper
shutdown
!
banner exec ^CEntering EXEC mode on R2901...^C
!
line con 0
line aux 0
line vty 0 4
password XXXXXXXX
login
transport input all
!
scheduler allocate 20000 1000
ntp server 200.186.125.195
end

Richard Bradfield · ‎01-17-2016

Hi have you tried

ip nat inside source list 1 interface gi0/0 overload instead you don't need the NAT pool then

and in case there is a restriction from the Internet modem

brcruz001 · ‎01-18-2016

Hi Richard,

Thanks for your reply. Another post caught my attention to a detail i didn't posted. Running "show ip route" I couldn't see my routing table. After checking another post I realized that ip routing was not enabled on the router.

After running the command "ip routing"on config, routing was enabled and the router's routing table was populated, enabling internet access to the computer behind it.

Thanks anyway for your help.

Regards

Cisco 2901 basic config for internet access