Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

PPP Multilink Bundle Monitoring

We had a 2xT1 PPP Multilink connection having performance problems. When I looked I noticed that the 2 serial interfaces were unevenly used. Did "sh ppp multilink" and saw that one of the T1's was "Inactive" in the bundle (SP problem, fixed quickly).

Does anyone have a better way to monitor this condition than "debug ppp multilink events" and watching the syslog? I don't see an SNMP trap for this. My interfaces were all UP but the connection was still lousy. Any ideas?


  • WAN Routing and Switching
New Member

Re: PPP Multilink Bundle Monitoring

An easy way to monitor the bundle and its interfaces' uptime is by using "show ppp multilink" You can get alot of info with 1 command such as bundle uptime, seperate interface uptime, lost fragments, etc. You can monitor for a couple of days and see if any counters increase. When I'm experiencing trouble with the bundle I always get a good look at each interface in the bundle by using "show interface serial 0/0/0:1" for example. Look for output drops and errors in general. Also keep an eye on the T1 controllers and watch for an increase in slips, PCVs, LCVs, ESs, etc.

Below is an example output from a clients 2811 w/ 2xT1.

gateway#sh ppp multi

Multilink1, bundle name is group81

Endpoint discriminator is group81

Bundle up for 1w3d, total bandwidth 3088, load 7/255

Receive buffer limit 24000 bytes, frag timeout 1000 ms

0/0 fragments/bytes in reassembly list

6 lost fragments, 1806609 reordered

0/0 discarded fragments/bytes, 0 lost received

0xAE3699 received sequence, 0x693D49 sent sequence

Member links: 2 active, 0 inactive (max not set, min not set)

Se0/1/0, since 1w3d

Se0/0/0, since 5d23h

No inactive multilink interfaces


Re: PPP Multilink Bundle Monitoring

Adam, thanks. I actually found the problem with "sh ppp multilink" but I am looking for an SNMP trap or MIB variable or something I can monitor. I am going to try an experiment with "debug ppp multilink events" but I always use debug with caution.

Thanx again.