Help with Configuring a 2811 Cisco Router for use with ISP

[Doctor Marmalade]

Hello!

So I found this 2811 Cisco router & wanted to hook it up in my house to use with my existing network equipment. 

I thought that it would be pretty straight-forward, but I can't seem to get it to work properly. I've looked online to find the correct commands, but none of them seem to be working right. 

After messing about with it for some time now, I've just erased the nvram, & reloaded the router until I get some proper info from you nice folks!

I'm not sure what info you may need in regards to how the router needs to be configured, but I'll provide what is necessary upon request. 

Thanks!

[Georg Pauwen]

Hello,

depends on where in your network the router needs to be. Can you provide a schematic drawing of what you have and where you want the router to be ?

[Doctor Marmalade]

Sure, so basically

ISP ---> 2811 ---> WiFi

or see photo for better idea. 

[Georg Pauwen]

Hello,

with your ISP connected to FastEthernet0/0 on your router, a basic configuration would look like this:

interface FastEthernet0/0
ip address dhcp
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
!
ip classless
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0
!
ip nat inside source list 1 interface FastEthernet0/0 overload
!
access-list 1 permit 192.168.1.0 0.0.0.255

[Doctor Marmalade]

Alright thanks. I'm going to give that a go right now. I'll let you know the results shortly.

As a side note, I used almost the same configuration as this before, only my default route wasn't the same as yours. That could have been one of my issues. 

Anyhow, I'll be back in a moment.

[Georg Pauwen]

Also, does the router interface connected to the modem pull an IP address ?

[Georg Pauwen]

Hello,

I have made a few adjustments to the config, give it a try (changes are marked in bold):

Current configuration : 1173 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption [redacted]
!
hostname [redacted]
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
enable secret [redacted]
!
no aaa new-model
!
dot11 syslog
ip source-route
!
ip cef
!
no ipv6 cef
!
multilink bundle-name authenticated
!
voice-card 0
!
archive
log config
hidekeys
!
interface FastEthernet0/0
ip address dhcp
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
!
interface Serial0/0/0
no ip address
shutdown
no fair-queue
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0
!
no ip http server
no ip http secure-server
!
ip nat inside source route-map ISP interface FastEthernet0/0 overload
!
access-list 1 permit 192.168.1.0 0.0.0.255
!
route-map ISP permit 10
match ip address 1
match interface FastEthernet0/0
!
control-plane
!
line con 0
password
login
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
end

[Georg Pauwen]

You also might want to log into the modem and find out the IP address assigned to it. Use that address in the default route. So instead of:

ip route 0.0.0.0 0.0.0.0 FastEthernet0/0

type

ip route 0.0.0.0 0.0.0.0 x.x.x.x (the IP address assigned to the modem)

[Doctor Marmalade]

Let me do that real quick. I didn't see this reply when I just posted. 

[Georg Pauwen]

Hello,

with the current configuration, your clients would need either static IP addresses or a DHCP assigned address from a server on your network.

You can also have the router dish out IP addresses. Add this to your config:

ip dhcp excluded-address 192.168.1.1

ip dhcp pool DHCP_LAN
 network 192.168.1.0 255.255.255.0
 dns-server 8.8.8.8 8.8.8.4
 default-router 192.168.1.1

[Doctor Marmalade]

OK, added the default-route via the modem's ip.

Also added the DHCP Pool as specified. 

Care for an updated running-config to help troubleshoot?

[Doctor Marmalade]

Building configuration...

Current configuration : 1379 bytes

!

version 12.4

service timestamps debug datetime msec

service timestamps log datetime msec

service password-encryption

!

hostname 

!

boot-start-marker

boot-end-marker

!

logging message-counter syslog

enable secret 

!

no aaa new-model

!

!

!

dot11 syslog

ip source-route

!

!

ip cef

!

ip dhcp pool DHCP_LAN

network 192.168.1.0 255.255.255.0

dns-server 8.8.8.8 8.8.8.4

default-router 192.168.1.1

!

!

no ipv6 cef

!

multilink bundle-name authenticated

!

!

voice-card 0

!

!

!

archive

log config

hidekeys

!

!

!

interface FastEthernet0/0

ip address dhcp

ip nat outside

ip virtual-reassembly

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 192.168.1.1 255.255.255.0

ip nat inside

ip virtual-reassembly

duplex auto

speed auto

!

interface Serial0/0/0

no ip address

shutdown

no fair-queue

!

ip forward-protocol nd

ip route 0.0.0.0 0.0.0.0 x.x.x.x (modem's ip add)

no ip http server

no ip http secure-server

!

!

ip nat inside source route-map ISP interface FastEthernet0/0 overload

!

access-list 1 permit 192.168.1.0 0.0.0.255

!

!

!

route-map ISP permit 10

match ip address 1

match interface FastEthernet0/0

!

!

!

control-plane

!

!

!

line con 0

password xxxxx7xx7x8x8x

login

line aux 0

line vty 0 4

login

!

scheduler allocate 20000 1000

end

[Doctor Marmalade]

Hold up...might be working now. My PC didn't want to pull an address right away, but I think it's got it now. Verifying...

[Doctor Marmalade]

Yep, looks like we got it now! Everything checks out good.

[Georg Pauwen]

Sorry I had to leave. Past midnight in my timezone...:)

Glad to hear it is working !