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Need help to rectify routing problems

aeonpoon
Occasional Advisor

Need help to rectify routing problems

Picture: http://i367.photobucket.com/albums/oo117/aeonpoon/vpn_topology_edited.jpg

I have tried static route on the routers but still cannot get both sides to ping.

FW1 routing table
ip route 0.0.0.0 0.0.0.0 192.168.10.2

R1 routing table
ip route 10.1.1.0 255.255.255.0 192.168.10.1
ip route 0.0.0.0 0.0.0.0 203.117.114.2

R2 routing table
ip route 0.0.0.0 0.0.0.0 203.117.120.9
ip route 0.0.0.0 0.0.0.0 203.117.114.1

R3 routing table
ip route 0.0.0.0 0.0.0.0 203.117.120.10
ip route 10.1.1.0 255.255.255.0 192.168.10.6

FW2 routing table
ip route 0.0.0.0 0.0.0.0 192.168.10.5

I wish anyone can help me out here cause I have never router 3 different subnets. Apperciate all the efforts

2 REPLIES
Mohammed Faiz
Honored Contributor

Re: Need help to rectify routing problems

Hi,

I'm assuming that you've not shown routes that are listed as "connected" in the routing tables for the routers/Firewalls?

There are quite a few issues there but the largest is this:

You are trying to route the same subnet to two different locations, i.e. PC1 and PC2 belong on the same LAN.

If PC1 and PC2 were on different subnets then the other problems are:

R1 - The route for 10.1.1.0/24 would have to change to whatever subnet PC1 exists on

R2 - Has two default routes, this is never normally used unless one is a backup route with a lower priority. It needs to have routes for the PC1 and PC2 subnets pointing to R1 and R3 respectively.

R3 - The same as R1 the route for 10.1.1.0/24 would have to change.

The easiest way to fix the issue would be to run a routing protocol across R1-R3, something like OSPF is quite simple to setup.
Pieter 't Hart
Honored Contributor

Re: Need help to rectify routing problems

I agree with mohammed

- two default routes on R2 will not work!
- both PC1 and PC2 belong to the same subnet
10.1.1.0/24 contains all adresses 10.1.1.1 to 10.1.1.254.

you must change subnets like
PC1 10.1.1.0/24 => adress 10.1.1.1/24
PC2 10.1.2.0/24 => addres 10.1.2.1/24

or
PC1 10.1.1.0/25 => adress 10.1.1.1/25
PC2 10.1.1.128/25 => adress 10.1.1.129/25

Change the R1 and R2 static routes according to the subnets used.

alternative to using a routing protocol to dynamically exchange subnet information you can add static routes on R2.
instead of
ip route 0.0.0.0 0.0.0.0 203.117.120.9
ip route 0.0.0.0 0.0.0.0 203.117.114.1
option-1:
ip route 10.1.2.0 255.255.255.0 203.117.120.9
ip route 10.1.1.0 255.255.255.0 203.117.114.1
option-2: one default route and one extra static route will work too:
ip route 0.0.0.0 0.0.0.0 203.117.114.1
ip route 10.1.2.0 255.255.255.0 203.117.120.9

if you connect an external network you should use option-1 and configure the default route to the external router.