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Webcast-Catalyst9k
New Member

2520 works, 1721 no

I have 1721 with ISDN. Isdn connection is ok but traffic is only 20 % successfully (20% pings are OK).

If I change router to 2520 - SAME CONFIG everything is 100% OK.

I tried :

-no encapsulation

-encapsulation ppp

-encap. and authent. chap

same result.

Only my good old 2520 works.

2 REPLIES
Bronze

Re: 2520 works, 1721 no

You don't indicate what the 1721 is connecting to, who is doing the dialing, or who is pinging, but to investigate the 1721 I would check the following:

clear counters

connect

debug ip error

ping

sh int (look for errors or drops under the B-channel interfaces)

(look for any debug output that may be associated with the pings)

sh buffer (if you are pinging the 1721, look for buffer misses or fails)

You should try different ping sources and destinations, too.

Silver

Re: 2520 works, 1721 no

The significant difference may be the IOS release rather than the platform. Try adding "no ip route cache" to the BRI interface. Some IOS releases seem to get confused with some dialer configurations without it.

Good luck and good hunting!

Vincent C Jones

www.networkingunlimited.com

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