Configure 2611 for use behind cable modem

[alexmtech]

Hi,
I currently have a cable modem with a Linksys Cable/DSL router using NAT to share my internet connection. For some reason the Linksys unit keeps freezing. I have a Cisco 2611 running IOS Version 12.2(5d). I want to configure the 2611 to pretty much do the same thing the Linksys is doing so I can use it to replace the Linksys unit. I tried this config that I gathered from a few different sources but it doesn't work. I am really new to the IOS CLI and understand most of the commands but not all of them. Anyway when I do a "show ip interface brief" command I get the following output:

Cisco2611c#show ip interface brief
Interface IP-Address OK? Method Status Protocol
Ethernet0/0 unassigned YES NVRAM up up

Ethernet0/1 192.168.1.1 YES NVRAM up up


I am assuming that the IP address for E0/0 would change when it acquires an IP from my cable provider's DHCP server. When I run the command it tells me unassigned so I am a guessing that interface is not getting an address. This is my current config. Can anyone tell me where I am making my mistakes or give me the exact code that would work for me in my situation. If possible maybe a brief description of what each section of code is actually doing. I really appreciate any help. Thanks in advance....!


Cisco2611c#show run
Building configuration...

Current configuration : 864 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Cisco2611c
!
enable secret 5 $1$5KZ8$xUcOUIY8pQp1WKPmpz3gO90
!
ip subnet-zero
!
!
ip name-server 24.29.99.81 <--- My ISP's DNS
ip name-server 24.29.99.82 <--- My ISP's DNS
ip name-server 24.29.99.28 <--- My ISP's DNS
ip dhcp excluded-address 192.168.1.1
!
ip dhcp pool HOME
network 192.168.1.0 255.255.255.0
default-router 192.168.1.1
dns-server 24.29.99.81 24.29.99.82 24.29.99.28
lease 0 2
!
!
!
!
interface Ethernet0/0
ip address dhcp
ip nat outside
half-duplex
!
interface Ethernet0/1
ip address 192.168.1.1 255.255.255.0
ip nat inside
half-duplex
!
ip nat inside source list 1 interface Ethernet0/0 overload
ip classless
no ip http server
ip pim bidir-enable
!
access-list 1 permit any
!
line con 0
line aux 0
line vty 0 4
password
login
!
no scheduler allocate
end

 

[tmCCNA]

I have a Cisco 806 running 12.1 and never could get it to work. My ISP finally got tired of all my emails and phone calls and gave me a static IP address for the same price. You may have to do the same. I am a Cisco Certified Network Associate and couldn't figure it out, nor anyone else in this forum. I think there are just some compatability issues with Cisco broadband routers, Cable Modems and ISP Hardware. Sorry, I couldn't help. Travis McGuire
CCNA, Network+, A+

 

[kcbell]

You are not getting an IP from your ISP. Try using the shutdown and no shutdown command after you enter the following at the console port or telnet:

enable
conf terminal
inter e0/0
shutdown
no shutdown

If you do it at the console port with logging turned on, you'll see the following:

Router(config-if)#no shutdown
Router(config-if)#Interface Ethernet0 assigned DHCP address 212.111.177.222, mask 255.255.255.0

.Feb 16 18:42:38.630: %LINK-3-UPDOWN: Interface Ethernet0, changed state to up
.Feb 16 18:42:39.638: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0,
changed state to up

Hope this help!

 

[BuckWeet]

Reset your cable modem.. Usually cable modems learn the MAC addresses and keeps them locked into their memory until you reset the power on it...


Reset the power with the Cisco hooked up and then try to get a lease again..


BuckWeet

 

[alexmtech]

Hey BuckWeet,
You hit the nail on the head..! I rebooted the cable modem and it worked like a charm. Now I feel stupid for not trying one of the basic troubleshooting steps. Thanks again to everyone for their help and suggestions, I really appreciate it.

Alex

 

[tmCCNA]

I'm glad your proplem was solved. Mine still will not get and IP address from my ISP, If I hook it up to a LAN with a DHCP server, it gets one just fine. I don't understand it, and now I have a static IP, so I guess it worked out for the best. Travis McGuire
CCNA, Network+, A+

 

[alexmtech]

Travis,
Don't feel bad dude you lucked out. I would much rather have a static IP, it gives you more stability and flexibility as far as what you can do. I started with a Linksys router, then purchased a Cisco uBR924 Cable Modem Router and after a tug of war with my ISP they decided they would not support the device on thier network since it is technically a Cable router and not just a simple cable modem. After many frustrating weeks of the Linksys freezing up on me I decided to try and use one of my Cisco 2600 routers. With some research and the help of everyone in this forum things are working, so far so good. My next step will be to upgrade the routers memory and load an IOS with firewall and VPN features. We'll see how that goes...!

Alex

 

[jerdog]

you might want to try &quot;pppoe enable&quot;(point to point over ethernet) command in interface mode.then you need to put the &quot;(config-dhcp)#netbios-name-server&quot; (your dns server), as well as the &quot;(config-dhcp)#domain-name (your domain).&quot; then you want to exclude adresses from getting assigned to your dns server. so in config mode use the command (config)#ip dhcp excluded-address 192.168.1.1 192.168.1.10. you also need to apply an access list to your e1 interface with the &quot;access-group 1 out&quot; that &quot;should&quot; work for you. of course in the world of computers, should is a relative term. good luck