EIGRP drops in a dialer interface(BRI connection)

[ruben.montes]

I have EIGRP running between two C2621 routers in an ISDN BRI connection. The performance of this line is very bad and users complaint about slow connections.

I have a lot of messages of this type almost of the type:

Sep 29 01:48:56: %DUAL-5-NBRCHANGE: IP-EIGRP 1: Neighbor 33.1.13.10 (Tunnel0) is down: holding time expired

Sep 29 01:48:58: %DUAL-5-NBRCHANGE: IP-EIGRP 1: Neighbor 33.1.13.10 (Tunnel0) is up: new adjacency

My theory is that the line is congested due to the high volume of traffic (utilization is about 175/255)

and some of the EIGRP hellos are being lost for that reason, causing the traffic to be changing their path almost all the time.

I know that by default, in a low speed(less than T1) WAN connection, like the one that I have, the EIGRP timers are bigger (hellos 60sec, holdtime 180sec). I've checked this in the routers and the timers are the same than in a LAN (hellos 5sec, holdtime 15sec).

Changing the timers would improve EIGRP the behavior?

If not, could anyone point me to a right solution?

Many thanks for your help.

Ruben

[rais]

Yes, changing timer can help you. You can also think about turning on QoS on this line to prefer one traffic over the other.

HTH.

[ruwhite]

I probably wouldn't change my timers to anything more than 30 second hello and 90 second hold timers on this link. Hello's are already marked as priority traffic, and should be preferred on the inbound and outbound side, without any qos configuration.

:-)

Russ.W