cisco static routing problem

[suranji]

Hi
I am having a problem to ping serial interface from same router. But I can ping any interface which is connected through same serial interface.

routing table is like this: (given below)

I feel somthing wrong in routing table itsenf and anybody got similar situation pls help me

Thanks
-suranji
=========================================================
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 0.0.0.0 to network 0.0.0.0

xxx.xxx.xxx.0/24 is variably subnetted, 2 subnets, 2 masks
C xxx.xxx.xxx.2/32 is directly connected, Serial2/0
C xxx.xxx.xxx.0/30 is directly connected, Serial2/0
yyy.yyy.yyy.0/24 is variably subnetted, 2 subnets, 2 masks
C yyy.yyy.yyy.3/32 is directly connected, Loopback0
C yyy.yyy.yyy.64/26 is directly connected, FastEthernet0/0
zzz.zzz.zzz.0/29 is subnetted, 1 subnets
S zzz.zzz.zzz.8 [1/0] via xxx.xxx.xxx.2
S* 0.0.0.0/0 is directly connected, FastEthernet0/0

 

[routerman]

First, do you have any access-lists on the interfaces?

Most likely though if your using static routing only is that the destination router does not have a route back to the IP subnet that is applied on the WAN port of the router you are pinging from. Your destination probably has no need to know a route back to that WAN subnet.

When you ping from the router its self the IP packet uses the IP address of the interfacefrom which it leaves the router as its source. You could try ping with the source address option set, just type ping and follow the prompts, use the ethernet Ip address as the source address.

Andy CCIE 7123

 

[suranji]

HI Andy

Thanks for the quick reply.

Destination router has default route to the router that i am pinging from.

Once i used the extended ping using ethernet address and loopback address also it fails. I can ping any other interface except whi are blocked by my routing table.

further help highly apreciated
-Thanks
suranji

 

[benduncan]

Can you post the output from show interface?

 

[suranji]

Hi

Here is the "sh int s2/0" output
==========================================================
Serial2/0 is up, line protocol is up
Hardware is CD2430 in sync mode
Internet address is xxx.xxx.xxx.1/30
MTU 1500 bytes, BW 128 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, loopback not set
Keepalive set (10 sec)
LCP Open
Listen: CDPCP
Open: IPCP
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 03:53:55
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/32 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 96 kilobits/sec
5 minute input rate 1000 bits/sec, 2 packets/sec
5 minute output rate 1000 bits/sec, 2 packets/sec
10453 packets input, 604012 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
10090 packets output, 542372 bytes, 0 underruns
0 output errors, 0 collisions, 32 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

 

[routerman]

Looking at your routing table in the first post I see the following.
C xxx.xxx.xxx.2/32 is directly connected, Serial2/0
S zzz.zzz.zzz.8 [1/0] via xxx.xxx.xxx.2

This indicates that x.x.x.2 is the IP address of the S2/0 interface on this router, and your static route is pointing at this address. The static should point to the IP address of the interface at the other end of the serial interface.
Could this be causing your problem?

 

[suranji]

Hi

Actually xxx.xxx.xxx.2/30 is the ip address of router at the other end. and s2/0 ip address is xxx.xxx.xxx.1/30. you can see the second post.

My biggest problem is "sh ip route " gives two "C" routes to same subnet. It is the problem that i am facing pinging also.

Thanks
-suranji

 

[croxo]

The first of these connected routing entries shows a 32 bit mask in use. Check your remote router Serial interface address - it should be xxx.xxx.xxx.2 255.255.255.252
I have a feeling you may have configured a mask of 255.255.255.255

C xxx.xxx.xxx.2/32 is directly connected, Serial2/0
C xxx.xxx.xxx.0/30 is directly connected, Serial2/0

 

[suranji]

Hi

I checked the router at the other end and its configuration is xxx.xxx.xxx.2/30. It is Intel express router and using ppp wan connection with cisco 3660 router at our end.

-thanks
suranji

 

[croxo]

How about you perform debug on ip icmp and then perform your ping, this may give a clue.


If I understand your problem correctly you are unable to ping the serial interface on your own router even though you are able to ping remote interfaces using this link.

Are you able to ping the remote end of the link xxx.xxx.xxx.2 ?

 

[suranji]

Hi croxo

Yes you are correct. I can all the interfaces including xxx.xxx.xxx.2 in the serial interface except my own serial interface (xxx.xxx.xxx.1). I can ping xxx.xxx.xxx.1 from other routers connected to the network .

Still problem is there.

Thanks
-suranji

 

[croxo]

The following URL refers specifically to pinging a serial interface on the same router it may be of some use to you.

http://www.dalantech.com/cisco-ts.shtml

 

[subbu4you]

Hi

Is the problem still exists ? If so can you send me your router configuration ? I will try to help you.

Thanks