Routing issues between dedicated Point to Point

Unanswered Question
Jun 3rd, 2008
User Badges:

I have 2 offices that are connected via T1 Point to point.

At this time i can ping from Router A to Router B and vice versa.

I can ping from Router A through Router A.1 to the internet and all the devices on network A. Router B can only ping its own interfaces and the Router A interfaces.

static Routes are setup using the Serial 0/0/0 interfaces as the forwarding ports.

I can for the life of me not firgure out what i have missing to get this connection to work. Netowrk B needs to be able to see Network A and also access the internet through Network A (Router A.1)

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Richard Burts Tue, 06/03/2008 - 18:25
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN


It would be helpful if you would provide specifics of the static routes on both routers and the IP addressing of both routers. Given your description of the symptoms there are several things that might be the problem:

- router B can ping router A because that is over a connected subnet, but perhaps there are not correct routes on router A for the connected subnets on router B.

- perhaps router B does not have a correct default route.

- perhaps the devices on router B do not have correctly configured default gateways.

- perhaps the addresses on router A are being correctly translated for access to the Internet but addresses from router B are not translated correctly.



steveo123 Tue, 06/03/2008 - 23:39
User Badges:

Rick has made a good point, the only thing i would like to add is: if you are using static routing for reach ability, then your static routing must be configured to point all network B subnet towards Router A's point-to-point facing IP, and the same thing from router B's perspective, to reach "network A" then route to router A's Point-to-point facing IP address.

In other words static routing must be configured on both sides to point to each other. When you issue the "sh IP route" COMMAND ON THE ROUTER you will see (if u r only running static routing) the subnet that is learned via "connected" this would be urr p-to-p link and what ever your static routing is configured for. So for the router to forward any traffic it must do a recursive route lookup, in your case the router would only know how to recuse the p-to-p link and its associated subnet.

easy way to trouble-shoot, just issue the debug IP packet and then run ping test, see what kind of errors u are receiving...

steve K

lamav Wed, 06/04/2008 - 04:18
User Badges:
  • Blue, 1500 points or more

perhaps you can post the configs to make it easier tohelp you..


lamav Wed, 06/04/2008 - 04:18
User Badges:
  • Blue, 1500 points or more

perhaps you can post the configs to make it easier to help you..



This Discussion