I have a P2P T1 connection between two offices connected by Cisco 2651XM routers with VWIC-2MFT-T1 cards. Last week I lost connectivity to site B so no one in the office could do anything because the 2651XM is also the gateway router for their LAN. They were unable to ping the LAN interface (fa0/0) on the router and I was unable to ping the serial interface on th other end of the P2P. I had them cycle the power and it came back up with everything working.
This weekend the same thing happened. Connectivity was lost but there was no one in the office to reset the router. Since there was nothing mission critical going on at site B we were going to have them reset the router this morning. Then the line came back up 2 1/2 hours later only to go back down again. Then it came back up 9 1/2 hours later and has been up since. We had our provider check the T1 and they stated that they were able to hit both ends of the T1 cleanly when we were having an interruption in connectivity.
The following is what is in the log for the site B router:
Apr 13 05:33:36.001: %CONTROLLER-5-UPDOWN: Controller T1 0/1, changed state to down (AIS detected)
Apr 13 05:33:38.004: %LINK-5-CHANGED: Interface Serial0/1:0, changed state to reset
Apr 13 05:33:38.016: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 172.30.3.1 (Serial0/1:0) is down: interface down
Apr 13 05:33:39.006: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/1:0, changed state to down
Apr 13 09:33:41.262: %SYS-3-CPUHOG: Task ran for 35333 msec (3591642/0), process = Logger, PC = 803B13E4.
-Traceback= 803B13E8 8049374C 80496CE8
Apr 13 09:33:41.314: %CONTROLLER-5-UPDOWN: Controller T1 0/1, changed state to up
.Apr 13 09:33:41.458: %LINK-3-UPDOWN: Interface Serial0/1:0, changed state to up
.Apr 13 09:33:42.496: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/1:0, changed state to up
.Apr 13 09:34:13.439: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 172.30.3.1 (Serial0/1:0) is up: new adjacency
.Apr 13 13:34:14.169: %SYS-3-CPUHOG: Task ran for 34454 msec (3591340/0), process = ARP Input, PC = 8053FD58.
-Traceback= 8053FD5C 8049374C 80496CE8
I didn't have the log buffered for the router at site A so I don't know what it saw. The log messages above don't really help me with this issue. I see that there was an AIS detected but I don't know why. What additional logging can I turn on or troubleshooting can I do for this to try and figure out the cause? I enabled the logging buffer on the site A router but that doesn't help me right now.