routing question 1

[Roberti]

I have a problem. We have 2 routers:

router 1 (6506-msfc2, switch with router module) has three interfaces, e0, e1, e2.

e0: 10.1.0.1 255.255.0.0
e1: 10.4.0.1 255.255.0.0
e2: 162.87.23.151 255.255.255.240

router 2 (2500) has 2 interfaces, e0, s0

e0: 162.87.23.145 255.255.255.240
s0: 135.135.16.22 255.255.255.252

I've configured router 1 to use rip, and added networks:

10.1.0.0
10.4.0.0
162.87.23.144

gateway of last resort is 162.87.23.145 via network 0.0.0.0

When I try to ping (216.239.59.99) from a pc behind interface e1 on router 1, I get time outs. when I ping from the router to the same address it does work. When I ping e0 on router 1 from a PC behind interface e1 on router 1, it works. When I ping e0 on router 2 from a PC behind interface e1 on router 1, I get time outs. What is going wrong? Let me know if you need more info.

 

[Andyleates]

What is your PC's default gateway?

Andy Leates MCSE CCNA MCP+I

 

[Roberti]

The default gateway is 10.4.0.1

 

[billberge]

Are you running RIP v2 to support VLSM?

 

[Roberti]

Well, as it turns out router 2 only uses static routes (Until recently it was remotly managed by the internet provider), and router 1 uses RIP.

I disabled RIP on router 1 and made a static route:

0.0.0.0 0.0.0.0 162.87.23.145 (e0 on router 2)

I still can't ping from a PC to the outside, but from router 1 it goes well.

 

[bell1996]

Do a "show ip route" on router 2 and see if it knows about the networks attached to router 1. If not, put in some static routes on router 2.

Router 2 static routes:

ip route 10.1.0.0 255.255.0.0 162.87.23.151
ip route 10.4.0.0 255.255.0.0 162.87.23.151

 

[Roberti]

I've added the static route to router 2:

10.4.0.0 255.255.0.0 162.87.23.151

From the PC I can now ping both interfaces on router 2. But I still can't ping to the internet. What am I missing?

 

[NetEng631]

I maybe misunderstanding what you are doing. But From my understanding it looks like you are trying to ping an Internet address from a 10.x.x.x. 10.x.x.x is not routable on the internet and will be dropped. Use NAT.

When you ping it from the router it uses the 163.x.x.x address. You can prove this with the ext. ping commands.

If this is not what you are doing I apologies.

 

[Roberti]

You are completly right, I forgot al about nat.
I configured nat know and it works now.

Thanks alot everybody for the great help.

 

[NetEng631]

Glad to be of help. Thanks for the Star.

 

[tom11011]

Can I see your modified configuration with NAT, or the NAT values you added for my own curiousity?

 

[Roberti]

Here's what I did:

In the configuration of interfaces e0 + e1 on router 1 I added:

ip nat inside

On interface e2 I added: ip nat outside.

Then I added: ip nat pool "poolname" 162.87.23.152 162.87.23.152 prefix 28

And finaly: ip nat inside source list 7 pool "poolname" overload

The contents of access-list 7:

access-list 7 permit 10.4.0.0 0.0.255.255

I hope this is of use for you.

P.S. here's a good link: configure nat