1720 routing issue

[headrush]

i have two cisco 1720's connected using a t-1 crossover cable plugged into each end of the routers' CSU/DSU wics. on cisco1 the fasteth0 is plugged into a switch that connects to our LAN. The other router, cisco2's fasteth0 is connected to a single computer. I have static routes set on both computers. I can ping through each router and hit the ethernet ports on each router and their CSU/DSU's. That isnt the porblem.

The problem is when I ping from the single computer connected to Cisco2 through Cisco1 into the switch connected to our local LAN the ping does not know where to go. I am attempting to ping random machines on our gateway which are all on the same subnet as the ethernet port. It will see the ethernet port and ping it on Cisco1 but any ip addresses past that it will not see. What do I have to enable in routing in order to see the rest of the LAN?

I want to do this so that the single computer on Cisco2 will be able to get internet connectivity from our LAN via cisco2.


please help.

thanks,

headrush

 

[mheianna]

Do a show ip route in both routers, probably in the Cisco1 router doesn't exist a route pointing to the cisco1's fe0 and viceversa.

The default gateway in your workstation must be the ip adderss of the ciscox's fe0. Check it.

regards

 

[headrush]

when i check the ip route it shows the connection to the ethernet port. i can ping from one ethernet port to the other ethernet port on each router.

it just doesnt ping anything else beyond the ethernet port on the routers. is there a routing protocol that i have to use? what else can i try...

please help.

thanks

 

[svermill]

Best to attach configs (or at least your static route statements). You said you entered static routes on both computers. Did you mean both routers? Are they host routes or network routes? That is, did the static routes only point to the address of router interfaces or to the entire attached networks?

 

[headrush]

here is the route table:WAN#show ip route


Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.1.100.2/32 is directly connected, Serial0
C 10.1.100.0/24 is directly connected, Serial0
S 192.168.0.0/24 [1/0] via 10.1.100.2


Internal#show ip ro
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route

Gateway of last resort is 10.1.100.1 to network 0.0.0.0

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.1.100.1/32 is directly connected, Serial0
C 10.1.100.0/24 is directly connected, Serial0
C 192.168.0.0/24 is directly connected, FastEthernet0
S 192.168.1.0/24 [1/0] via 10.1.100.1
S* 0.0.0.0/0 [1/0] via 10.1.100.1
Internal#

i guess i would need to add a statement that points to the whole network because right now i can only ping the interfaces on each end. if this is not sufficient, please respond and i will give more information and make and suggested chances asap.

thanks again

 

[svermill]

Here is another question: Your hosts that you are trying to ping have a default gateway. Presumably, that default gateway is truly some gateway router that points to the internet as opposed to router 1 (or are they one and the same?). Does that gateway router know how to reach your lone host out there behind router 2? Because it may very well be that your pings are reaching those hosts, the hosts are trying to repond via thier default gateway, but the default gateway doesn't redirect to router 1 because it doesn't know that it should (and probably sends them up its default route to your ISP router unless an access list has been configured to prevent private ip space from going out to the ISP!).

If that isn't your issue, a little more detail on your architecture and configs might help. It's easy to miss the forest for the trees when you only have a little info to go on. Since I don't have a lab up and running at the moment, I'm curious about your static routes. Did you truly enter them as being via a local *ip address* or did you enter them as being via a local *interface* and the router just spit them out in the table as being via a local ip. I really can't remember what the Cisco behavior is in that regard. Normally, you enter a static route as via a local interface or a next hop ip address. That is, the distant-end serial ip as opposed to the local-end ip or just "S0," for example.

 

[khanduja]

Hi

It seems that u have 192.168 n/w on both ends of the routers. These being private ip-addresses; u need to NAT these so that they can talk to each other or try with different ip-addresses on one end of router and modify the static routes accordingly.

Cheers,
Khanduja

 

[headrush]

i tried to do it both ways. ill keep trying. thanks again for your help.

 

[svermill]

Did you ever determine if your default gateway on the hosts you can't ping is router 1 or something else?