Cable Modem problem...

[wannaciscobe]

Hi all,
Sorry for another cable modem problem. I see a lot of people have problems hooking them to routers...now I'm inluded in that crowd.

I have 2 2501's back to back and I"ve got full connectivity to and from both routers.
From the router connected to the internet I can ping using names or IP's to any internet site and have no problem.

From the router connected thru serial ports to this one I can ping all the way to E0 that is connected to my cable modem..but no farther...I have a PC connected to E0 of the other router and it also can only connect to EO at the cable modem.

You'll find both my config's below...can anyone help?


Router1 (connected to cable modem)

Building configuration...

Current configuration : 867 bytes
!
version 12.2
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname xxxxxxx
!
logging rate-limit console 10 except errors
enable secret 5 $1$7a8P$e97Nm6uQVrfIhYXE0hAT6.
!
no ip subnet-zero
no ip finger
ip name-server 65.xx.xx.xxx
ip name-server 65.xx.xx.xxx
!
no ip dhcp-client network-discovery
!
!
!
!
interface Ethernet0 (interface to cable modem)
mac-address 0080.c6ea.fa3e
ip address dhcp
ip nat outside
!
interface Serial0 (connected to S1 of other router)
ip address 10.xx.xx.x 255.255.255.0
ip nat inside
no fair-queue
clockrate 56000
!
interface Serial1
no ip address
shutdown
!
ip kerberos source-interface any
ip classless
ip route 0.0.0.0 0.0.0.0 24.210.112.1 (next hop)
ip route 169.254.0.0 255.255.255.0 10.10.10.2 (Ethernet connected to other router)
no ip http server
!
!
!
line con 0
transport input none
line aux 0
line vty 0 4
password xxxxxx
login
!
end




Router 2 (connected to other router)

Building configuration...

Current configuration : 763 bytes
!
version 12.2
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
logging rate-limit console 10 except errors
enable secret 5 $1$O78m$0yEEQarme3dUDwXnrEO4c0
!
no ip subnet-zero
no ip finger
ip name-server 65.xx.xx.xxx
ip name-server 65.xx.xx.xxx
!
no ip dhcp-client network-discovery
!
!
!
!
interface Ethernet0
ip address 169.xxx.x.x 255.255.255.0
!
interface Serial0
no ip address
encapsulation x25
shutdown
!
interface Serial1 (connected to S0 of router connected to internet)
ip address 10.xx.xx.x 255.255.255.0
!
ip kerberos source-interface any
ip classless
ip route 0.0.0.0 0.0.0.0 10.10.10.1
no ip http server
!
!
!
line con 0
transport input none
line aux 0
line vty 0 4
password xxxxxx
login
!
end

 

[CCIEWANNABE]

Does your Ip provider Provide you with a DHCP Address or Static address. Route once; switch many

 

[wannaciscobe]

Cciewannabe,
They provide a DHCP address.
bob

 

[rburke]

Try using this link, it has a single router's configuration for cable modem, as well as desriptions on what the commands are doing. One of the regulars on this page created the site.

http://packetattack.com/cisco-cable.html

Let me get straight what your setup is right now.

PC----------Router 2 +++++++++++++++ Router 1 ------- Modem
169.xxx.x.x/24 10.xx.xx.x/24 DHCP

I think what you are missing is the NAT/PAT commands. What you're going to need to do is NAT/PAT twice. On Router 2, you are going to have to NAT/PAT the 169.xxx.x.x/24 to the
10.xx.xx.x/24, then once you get to Router 1, you are going to have to NAT/PAT the 10.xx.xx.x/24 to the dhcp address given to you by your ISP. The link above will show you how to do Router 1, and the Router 2 will be very similar, infact, it could e the same if you setup DHCP on Router 1. But take a look at that link and see if it helps, like I said it should help with at least Router 1. If you have any more questions let us know.

burke

 

[rburke]

One more thing... I would avoid the 169.xxx.x.x IP addresses. They are typically used for Windows as junk addresses if it cannot find a DHCP server and are reserved for that function. I don't know what would happen if you started using those as routeale Ips. I would recommend the 192.168.x.0 255.255.255.0 instead. Just an idea.

burke

 

[jpapanik]

Also you may want to consider setting up a static route from the router inside your network (R2 S1) to the router outside your network (R1 S1). Just a thought.

 

[wannaciscobe]

Thanks very much, all of you....
I'll check it out when I get home....

bob

 

[wannaciscobe]

rburke,
I checked out the link you mentioned...it's done using a router with 2 ethernet ports. Do I have to do the nat/pat thing twice because I'm doing a back-to-back serial link?

Thanks for the info....

bob