mulitlink ppp stops responding when any link is dropped

Unanswered Question
Jan 12th, 2009

Does anyone understand why a Mutlilink interface would stay up but stop responding to a ping _for_approx_60_secs_ when any of the individual T1 interfaces in the bundle go down? The output of "sh int multi2" indicates that packets are flowing out and IN but I'm not able to ping several hosts (all that i tried) at the far end.

Here's a sanitized copy of the config which hasn't changed recently.

!!!7200!!!!

interface Serial2/6:0

no ip address

encapsulation ppp

ppp multilink

ppp multilink group 2

!

interface Serial2/7:0

no ip address

encapsulation ppp

ppp multilink

ppp multilink group 2

interface Multilink2

ip address 10.10.12.1 255.255.255.252

ppp multilink

ppp multilink group 2

7200#sh int multi2

Multilink2 is up, line protocol is up Hardware is multilink group interface

Internet address is 10.10.12.1/30

MTU 1500 bytes, BW 1536 Kbit, DLY 100000 usec, reliability 255/255, txload 9/255, rxload 6/255

Encapsulation PPP, LCP Open, multilink Open

Open: IPCP, loopback not set

Keepalive set (10 sec)

DTR is pulsed for 2 seconds on reset

!!!!2800!!!!

interface Multilink1

bandwidth 3072

ip address 10.10.12.2 255.255.255.252

ip nbar protocol-discovery

no cdp enable

ppp multilink

ppp multilink group 1

!

interface Serial0/0/0:0

no ip address

encapsulation ppp

ppp multilink

ppp multilink group 1

!

interface Serial0/0/1:0

no ip address

encapsulation ppp

ppp multilink

ppp multilink group 1

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
Collin Clark Mon, 01/12/2009 - 14:14

We ran into this once and it was a bug in IOS. I don't have all the relevant info right now, try searching your IOS in BugTrack.

Hope that helps.

reachonenetadm Tue, 01/13/2009 - 08:45

I'm running a 7200 with 12.(9)T2. Bug ID CSCek75294 is close, but the hardware doesn't match. (i've tried both PA-MC-4T1 and PA-MC-8T1 on the 7200 side and a 2600 with NM-4T and 2821 at the far end). Thanks anyway though. I'll keep searching.

reachonenetadm Tue, 01/13/2009 - 08:46

additional info, it's not just ping traffic that's affected. Client applications (telnet for example) also fail during the 'transition'

Actions

This Discussion