routing help 1

[mattl72]

I'm setting up a test lab in order to prepare for my CCNA but I'm having trouble getting Internet (connected through a cable modem) into my routed network. My current config is as follows:

I have two Cisco 1600 series routers connected through a serial cable. Router A Ethernet 0's interface is assigned 192.168.3.254. Serial 0's is assigned 10.1.1.251. Router B's Ethernet 0's interface is connected to 192.168.2.254, with Serial 0 interface assigned 10.1.1.252. I also have a firewall running NAT connected to the internet. Its WAN interface has been configured for DHCP and currently has a 20.24.132.x address with a subnet mask of 255.255.254.0. Its LAN address has been configured with 192.168.3.1.

I cannot figure out how to get the internet to route to the PCs. I tried adding a route that points to the WAN connection on the firewall on Router A but no luck.

Any suggestions? Its a pretty simple network and I know its just a matter of configuring a route in the right place(s) but I can't tell where it goes.

TIA,
Matt

 

[ChrisAC]

The firewall on network A will need a route to network B via router A. Router A will need a static route to network B via router B and router B will need a default route via router A.

Chris.


**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[gaveeve]

Need configurations.

 

[mattl72]

Thanks for your replies...

The network routes correctly between the eth0 subnets on Router A and Router B - I can ping from both sides. I can also access the internet on the 192.168.3.0 network if the default gateway points to the firewall (192.168.3.1). I just added the following route to the firewall

IP Route 192.168.2.0 255.255.255.0 192.168.3.254

I still cant get to the Internet from the 192.168.2.0 subnet though. Anyway, heres the config for the routers:

Router B -

version 11.3
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
service udp-small-servers
service tcp-small-servers
!
hostname RouterB
!
process-max-time 200
!
interface Ethernet0
ip address 192.168.2.254 255.255.255.0
!
interface Serial0
ip address 10.1.1.252 255.255.255.0
encapsulation ppp
!
interface BRI0
no ip address
shutdown
!
no ip classless
ip route 192.168.3.0 255.255.255.0 10.1.1.251
!
!
line con 0
password conpass
login
line vty 0 3
login
line vty 4
password telpass
login
!
end

-----------------------------------------------------------
Router A -

version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
service udp-small-servers
service tcp-small-servers
!
hostname routerA
!
ip subnet-zero
!
!
!
interface Ethernet0
ip address 192.168.3.254 255.255.255.0
no ip directed-broadcast
!
interface Serial0
ip address 10.1.1.251 255.255.255.0
no ip directed-broadcast
encapsulation ppp
clockrate 64000
!
no ip classless
ip route 192.168.2.0 255.255.255.0 10.1.1.252
!
!
line con 0
password conpass
login
transport input none
line 1
line vty 0 4
password telpass
login
!
end

 

[gaveeve]

Your static routes on B:
ip route 0.0.0.0 0.0.0.0 10.1.1.251, this sends internet traffic toward A.
Your Static routes on A:
1.ip route 0.0.0.0 0.0.0.0 192.168.3.1, this sends internet traffic toward the firewall.
2.the one you already have.
Your Static route on Firewall:
ip route 192.168.2.0 255.255.255.0 192.168.3.254, sends traffic for E0 on B towards A. (as iproute says)

 

[mattl72]

That worked - thank you so much!

So 0.0.0.0 basically tells all traffic to go out a particular interface?

Don't know if this makes a different or not, everything seems to be working fine, but I can't ping an Internet address on Router B. It works on Router A.