Help with WAN routing issue...

[stownsend]

I've jsut put in anohter WAN Segment into my network and I cannot always get traffic to the new routers.

The setup is as follows

Internet <--> PIX <---> R1:2620<--frame--> R2:1721<--Enet-->R3:2500<--T1-->R4:2514<--enet-->R4-Host

PIX:

INSIDE:10.1.0.2 255.255.0.0

PPTP Pool:10.201.0.1-10.201.0.254

access-list inside_nat permit ip 10.0.0.0 255.0.0.0 10.201.0.0 255.255.255.0

nat (inside) 0 access-list inside_nat

nat (inside) 1 10.0.0.0 255.0.0.0 0 0

R1:

E0: 10.1.0.1 255.255.0.0

S0/0.1: 10.254.0.1 255.255.255.252

R2:

E0:10.2.0.1 255.255.0.0

S0/0.1: 10.254.0.2 255.255.255.252

R3:

E0:10.2.0.3 255.255.0.0

S0:10.254.0.21 255.255.255.252

R4:

E0:10.3.0.1 255.255.0.0

S0:10.254.0.22 255.255.255.252

R1 can ping a host on the far side of R4 with no problems.

PIX can ping a host on the far side of R4 with no problems.

Host connecting from internet to PIX can ping R2 with no problems.

My Problme is that a Host connecting from internet to PIX can not ping R3!!

The Ethernet interface on R3 is on the same LAN as R2.

When I run a Trace to R3 from the intenet host I can get to R2 and then it Dies. If I trace from R3 to the internet host, it just gives me * * *.

What Gives??

Thanks,

Scott<-

[thisisshanky]

R3 should have a default route on its routing table, pointing to R2, so that for the packets coming from the host in the internet, replies can be sent back. Check this out.

[stownsend]

I've included the routing table for R1, R2 and R3 below.

The Addresses that the PIX assigns the PPTP Clients is 10.201.0.X.

Its not in any of the routing tables, though all of the Default routes point to the next hop closest to the PIX, which knows about the 10.201.0.x network.

Since I'm not trying to conenct to R4 at this point I dont think it matters, but It is also connected to the internet. E0 is conencted to DSL and E1 is connected to a local LAN 10.3.x.y. Its default route is E0 then S0(R3), So its first hop for all unknown address is first the DSL internet, not R3.

Anything else to try??

Thanks!

Scott<-

Here is the Routing Table for R3, Its Default route is R2's E0 port..

Gateway of last resort is 10.2.0.1 to network 0.0.0.0

10.0.0.0/8 is variably subnetted, 13 subnets, 3 masks

D 10.10.1.0/24 [90/2744320] via 10.2.0.1, 00:25:00, Ethernet0

C 10.2.0.0/16 is directly connected, Ethernet0

D 10.3.0.0/16 [90/2195456] via 10.254.0.22, 00:25:00, Serial0

D 10.1.0.0/16 [90/2206720] via 10.2.0.1, 00:25:00, Ethernet0

D 10.4.0.0/16 [90/2206720] via 10.2.0.1, 00:25:00, Ethernet0

D 10.5.0.0/16 [90/2206720] via 10.2.0.1, 00:25:00, Ethernet0

D 10.254.0.32/30 [90/2718720] via 10.2.0.1, 00:25:00, Ethernet0

C 10.254.0.20/30 is directly connected, Serial0

D 10.254.0.16/30 [90/2204160] via 10.2.0.1, 00:25:00, Ethernet0

D 10.254.0.4/30 [90/2716160] via 10.2.0.1, 00:25:00, Ethernet0

D 10.254.0.0/30 [90/2204160] via 10.2.0.1, 00:25:00, Ethernet0

D 10.254.0.12/30 [90/2204160] via 10.2.0.1, 00:25:00, Ethernet0

D 10.254.0.8/30 [90/2716160] via 10.2.0.1, 00:25:00, Ethernet0

S* 0.0.0.0/0 [1/0] via 10.2.0.1

Here is the Routing Table for R1, Its Default route is PIX's INSIDE interface..

Gateway of last resort is 10.1.0.2 to network 0.0.0.0

10.0.0.0/8 is variably subnetted, 13 subnets, 3 masks

D 10.10.1.0/24 [90/2198016] via 10.1.0.3, 3d18h, FastEthernet0/0

D 10.2.0.0/16 [90/2181120] via 10.254.0.2, 3d18h, Serial0/0.1

D 10.3.0.0/16 [90/2718720] via 10.254.0.2, 00:29:14, Serial0/0.1

C 10.1.0.0/16 is directly connected, FastEthernet0/0

D 10.4.0.0/16 [90/2181120] via 10.254.0.6, 3d18h, Serial0/0.2

D 10.5.0.0/16 [90/2181120] via 10.254.0.10, 3d18h, Serial0/0.3

D 10.254.0.32/30 [90/2172416] via 10.1.0.3, 3d18h, FastEthernet0/0

D 10.254.0.20/30 [90/2693120] via 10.254.0.2, 00:31:30, Serial0/0.1

D 10.254.0.16/30 [90/2690560] via 10.254.0.2, 3d18h, Serial0/0.1

[90/2690560] via 10.254.0.10, 3d18h, Serial0/0.3

C 10.254.0.4/30 is directly connected, Serial0/0.2

C 10.254.0.0/30 is directly connected, Serial0/0.1

D 10.254.0.12/30 [90/2690560] via 10.254.0.2, 3d18h, Serial0/0.1

C 10.254.0.8/30 is directly connected, Serial0/0.3

S* 0.0.0.0/0 [1/0] via 10.1.0.2

For Kicks here is the Routing on R2

Gateway of last resort is 10.254.0.1 to network 0.0.0.0

10.0.0.0/8 is variably subnetted, 13 subnets, 3 masks

D 10.10.1.0/24 [90/2718720] via 10.254.0.1, 3d18h, Serial0.1

C 10.2.0.0/16 is directly connected, FastEthernet0

D 10.3.0.0/16 [90/2198016] via 10.2.0.3, 00:46:02, FastEthernet0

D 10.1.0.0/16 [90/2181120] via 10.254.0.1, 3d18h, Serial0.1

D 10.4.0.0/16 [90/2181120] via 10.254.0.14, 3d18h, Serial0.2

D 10.5.0.0/16 [90/2181120] via 10.254.0.18, 3d18h, Serial0.3

D 10.254.0.32/30 [90/2693120] via 10.254.0.1, 3d18h, Serial0.1

D 10.254.0.20/30 [90/2172416] via 10.2.0.3, 00:48:18, FastEthernet0

C 10.254.0.16/30 is directly connected, Serial0.3

D 10.254.0.4/30 [90/2690560] via 10.254.0.1, 3d18h, Serial0.1

C 10.254.0.0/30 is directly connected, Serial0.1

C 10.254.0.12/30 is directly connected, Serial0.2

D 10.254.0.8/30 [90/2690560] via 10.254.0.1, 3d18h, Serial0.1

[90/2690560] via 10.254.0.18, 3d18h, Serial0.3

S* 0.0.0.0/0 [1/0] via 10.254.0.1

[mark_cairns · Accepted solution]

Are you running ip classless on all routers, especially #3?

[stownsend]

no I am not.

What is it and why do I want to run it?

Thanks,

Scott<-

[mark_cairns · Accepted solution]

When running no ip classless, the router will assume that if there is a route in it's tables for any subnet, it should know all routes within that class. You have routes for subnets that fall within 10.0.0.0 class A. Any traffic arriving at that router destined for a subnet within 10.0.0.0, that does not have a specific route in your table, gets sent to null and dropped. The default route never gets checked because the router is looking for a route to 10.0.0.0 (supernet). By running ip classless, the router will use the default route (best supernet) if no specific route exists. Check the following link:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipras_r/1rfipadr.htm#1018036