Pinging Issue

[reb999000]

I am trying to communicate to my 2621XM router from my 3620 router by serial cable, and I am getting this result:

"

eastrouter#ping 200.100.11.6

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 200.100.11.6, timeout is 2 seconds:

.!.!.

Success rate is 40 percent (2/5), round-trip min/avg/max = 28/28/28 ms

eastrouter#ping 200.100.11.6

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 200.100.11.6, timeout is 2 seconds:

!.!.!

Success rate is 60 percent (3/5), round-trip min/avg/max = 28/29/32 ms

eastrouter#

"

I can telnet from the 3620 to the 2621XM.

I have doublechecked my DCE clockrate & "no shutdown" in my interfaces and I have ruled these out.

Please have a look at the extract of the pinging result that I have pasted, I would be greatful for any help.

Regards

Bob.

[Richard Burts]

Bob

You are on the right track to change the mask on southrouter to /30 but it is not enough. The real problem is on eastrouter. As long as both serial1/0 and serial1/1 have /24 masks the router will believe that it has 2 paths to 200.100.11.6 and your ping problem will continue. What you need to do is to change the mask on both serial interefaces on eastrouter.

HTH

Rick

[reb999000]

Rick,

I may have to "erase start-up config" on eastrouter and reconfigure the NVRAM for /30 addresses, as the current NVRAM is not accepting the /30 addresses. I know there is a quicker way around this.

Bob.

[Richard Burts · Accepted solution]

Bob

I do not believe that erasing startup-config is necessary. I suspect the problem is in the way that you are attempting to change the addresses. When you try to change the mask are you getting an error message about invalid mask? If so the reason is that the IP address you are attempting to configure on the interface is either the subnet address or is the subnet broadcast address. If that is not the issue then can you tell us what you are trying to configure and what error message you get when you try to change the config?

To make this discussion a bit easier can you post the addressing that you are trying to use on both serial interfaces and the addressing of the devices connected on each of the serial interfaces? They perhaps we can help you choose and implement addresses that will work?

HTH

Rick

[reb999000]

Rick,

I am only restricting the use of RIP/RIPv2 on the 2500 series routers as the /24 & /30 addresses communicates very well using RIPv2 as this supports VLSM.

Thank you very much for all your help!

Regards

Bob.