Experience: AI3 Bridge Configuration & troubleshooting

Last time the satellite transmission station for TU had just been shifted from AIT to SFC Japan. The major steps to be done for successful switchover was checking the satellite signal Eb/No. and changing the route configuration on FreeBSD router (our BDL gateway). What I had to do was just change configuration on serial interface of AI3 Bridge.

I got a bit trouble regarding the bridge configuration because I hadn’t have access to AI3 Bridge. Someone else had already set password of our SOI Bridge. No problem, I just reset the bridge (CISCO 1700 series router) password and kept backup of all bridge configuration. The bridge has two interfaces (fastethernet0>>LAN interface and serial0>>satellite interface). I just changed the configuration on serial interface like this (which is given by Husni-san from SFC)

interface Serial0
description satellite
no ip address
no ip route-cache
no ip mroute-cache
no keepalive
no fair-queue
ignore-dcd
serial restart-delay 0
bridge-group 1
bridge-group 1 spanning-disabled
hold-queue 16 out

By the way, this configuration didn’t work. I couldn’t see neighboring bridge. I used the command “show bridge” and “show cdp neighbor”. Both commands displays nothing on the hyperterminal. But the magic part was: all signal status were up with serial0 interface.

DCD=up DSR=up DTR=up RTS=up CTS=up.

I just roamed and wait response from Husni-san. Husni conformed that the problem should be on link. Finally Abazh and Me started troubleshooting online over the link. As per the suggestion from Abazh-san, I just removed the ignore-dcd (Data Carrier Detect) and no keepalive line from the configuration. Then it works ha ha ha…. Due to this problem TU-SFC connectivity was down more than a week. Hence, it indicates that I must have more experiences regarding bridge configuration (what each line of configuration do?).