Hi Maamun, I had a similar problem when setting a network connecting two 2500. The line protocol on a serial interface would continuously go up and down. After little bit of troubleshooting, i finally boiled it down to the fact that the serial port on one of the routers was faulty. So try replacing the router (if its not a production box) or try using another serial interface (if its available) and see if that solves your problem.
Good luck, Imran Moin. --- maamun Murangwa wrote: > Hi, > > I'm having a problem with a serial interface line > protocol going up and down every few seconds. All i > can see is the the carrier trasitions increasing, > this > is a fiber link, so i presume, there shouldn't be > alot > of errors. I have changed the cable, still no luck. > Telco still says they have run loops and dont see > any > thing wrong with the link. I have also changed encap > to PPP, still no luck > Attached is the show interface output > > > Serial1/5 is up, line protocol is up > Hardware is M8T-X.21 > Description: Bussiness Systems Ltd > Internet address is 212.xx.xx.xx/30 > MTU 1500 bytes, BW 1024 Kbit, DLY 20000 usec, > reliability 172/255, txload 1/255, rxload 1/255 > Encapsulation HDLC, crc 16, loopback not set > Keepalive set (10 sec) > Last input 00:00:02, output 00:00:02, output hang > never > Last clearing of "show interface" counters > 04:58:14 > Input queue: 0/75/0 (size/max/drops); Total output > drops: 0 > Queueing strategy: weighted fair > Output queue: 0/1000/64/0 (size/max > total/threshold/drops) > Conversations 0/8/256 (active/max active/max > total) > Reserved Conversations 0/0 (allocated/max > allocated) > 5 minute input rate 0 bits/sec, 0 packets/sec > 5 minute output rate 1000 bits/sec, 1 packets/sec > 208 packets input, 4992 bytes, 0 no buffer > Received 0 broadcasts, 0 runts, 0 giants, 0 > throttles > 3946 input errors, 3059 CRC, 0 frame, 17 > overrun, > 0 ignored, 870 abort > 5703 packets output, 451522 bytes, 0 underruns > 0 output errors, 0 collisions, 707 interface > resets > 0 output buffer failures, 0 output buffers > swapped out > 707 carrier transitions DCD=up DSR=up > DTR=up RTS=up CTS=up > --More-- > *Mar 28 03:25:33.997 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to down > *Mar 28 03:28:24.013 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to up > *Mar 28 03:28:44.025 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to down > *Mar 28 03:29:34.029 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to up > *Mar 28 03:29:54.029 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to down > *Mar 28 03:31:24.037 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to up > *Mar 28 03:31:26.029 gmt: %LINK-3-UPDOWN: Interface > Serial1/5, changed state to > up > *Mar 28 03:31:54.061 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to down > *Mar 28 03:32:04.057 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to up > *Mar 28 03:32:34.065 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to down > *Mar 28 03:32:44.065 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to up > *Mar 28 03:33:04.065 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to down > *Mar 28 03:33:14.065 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to up > *Mar 28 03:33:34.073 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to down > *Mar 28 03:34:34.081 gmt: %LINEPROTO-5-UPDOWN: Line > protocol on Interface Serial > 1/5, changed state to up > *Mar 28 03:34:36.073 gmt: %LINK-3-UPDOWN: Interface > Serial1/5, changed state to > up > > > Thanx in advance > > Maamun > > __________________________________________________ > Do You Yahoo!? > Everything you'll ever need on one web page > from News and Sport to Email and Music Charts > http://uk.my.yahoo.com [EMAIL PROTECTED] ===== Imran Moin Network Engineering and Operations University of Colorado, Boulder CCNA, CCNP (switching) __________________________________________________ Do You Yahoo!? Yahoo! Movies - coverage of the 74th Academy Awards. http://movies.yahoo.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=39825&t=39766 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
