From: Sasa Milic (smilic2@pexim.co.yu)
Date: Thu Apr 13 2006 - 08:22:18 GMT-3
Ivan,
I had similar case but Cat2950 switches were involved, and because of some
loop they suddenly started to shutdown uplinks with the same message. TAC
solution
was to enter "no keepalive" on each port. What's interesting is that 3500-XL
switches, also deployed at customer site, have "no keepalive" as default.
Cisco said that "no keepalive" will be default in newer ios versions.
Regards,
Sasa
----- Original Message -----
From: "Ivan" <ivan@iip.net>
To: <ccielab@groupstudy.com>
Sent: Thursday, April 13, 2006 1:03 PM
Subject: OT: LOOP_BACK_DETECTED
> Hello group !
>
> Real life situation. There is 15 switches (Cat 3500 & Cat 3550)
> connected
> sequence. Some times ago LOOP_BACK_DETECTED appear on Gigabit interface
> and
> port go down. This situation repeat some times between the same switches.
> I
> know that neither Cables nor GBIC's don't modify or touched at accident
> time.
> CISCO site give poor information about this error.
> "This message means that the loop-back condition might be caused by a
> balun
> cable being accidentally plugged into the port. [chars] is the port."
>
> Does someone has such situation ? And what real cause this accident ?
>
> show version on switch wich LOOP_BACK_DETECT
> SW-2#sh ver
> Cisco Internetwork Operating System Software
> IOS (tm) C3550 Software (C3550-I5Q3L2-M), Version 12.1(11)EA1, RELEASE
> SOFTWARE (fc1)
> Copyright (c) 1986-2002 by cisco Systems, Inc.
> Compiled Wed 28-Aug-02 10:03 by antonino
> Image text-base: 0x00003000, data-base: 0x0071D658
>
> ROM: Bootstrap program is C3550 boot loader
>
> Giga-IOC uptime is 1 hour, 0 minutes
> System returned to ROM by power-on
> System restarted at 13:27:17 MSD Thu Apr 13 2006
> System image file is "flash:c3550-i5q3l2-mz.121-11.EA1.bin"
>
> cisco WS-C3550-24 (PowerPC) processor (revision J0) with 65526K/8192K
> bytes of
> memory.
> Processor board ID CAT0727Y0A3
> Last reset from warm-reset
> Bridging software.
> Running Layer2/3 Switching Image
>
> Ethernet-controller 1 has 12 Fast Ethernet/IEEE 802.3 interfaces
>
> Ethernet-controller 2 has 12 Fast Ethernet/IEEE 802.3 interfaces
>
> Ethernet-controller 3 has 1 Gigabit Ethernet/IEEE 802.3 interface
>
> Ethernet-controller 4 has 1 Gigabit Ethernet/IEEE 802.3 interface
>
> 24 FastEthernet/IEEE 802.3 interface(s)
> 2 Gigabit Ethernet/IEEE 802.3 interface(s)
>
> The password-recovery mechanism is enabled.
> 384K bytes of flash-simulated non-volatile configuration memory.
> Base ethernet MAC Address: 00:0D:65:12:9E:00
> Motherboard assembly number: 73-5700-10
> Power supply part number: 34-0966-02
> Motherboard serial number: CAT072702G9
> Power supply serial number: DTH07260BGH
> Model revision number: J0
> Motherboard revision number: A0
> Model number: WS-C3550-24-SMI
> System serial number: CAT0727Y0A3
> Configuration register is 0x10F
>
>
>
>
> --
> Ivan
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Mon May 01 2006 - 11:41:57 GMT-3