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New Member

Layer 3 3550 switch IOS Bug

Hi All

Perhaps someone has seen this problem before.

I have got a Layer 3 switch 3550 connecting to an Optical Laser unit at 2 buildings.

When the laser connects to the switch with its utp cable the port does not come up when I use the Later versions of IOS ie Version 12.1(12)EA1 and later up to 12.1(14)EA1.If I downgrade the switches to Version 12.1(11)EA1 it works and picks up the Laser units.

Is this a possible IOS bug.I cant upgrade my switches now because of this problem.Will the later version of software after 12.1(14)EA1 have a fix for this problem.Below is the version that is working with the Laser units at present.

Any ideas would be useful.


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

NCITL02S03 uptime is 4 weeks, 6 days, 21 hours, 10 minutes

System returned to ROM by power-on

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 CAT0730X0AW

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)

  • Other Network Infrastructure Subjects
Cisco Employee

Re: Layer 3 3550 switch IOS Bug

Try latest 12.1(19)EA1 and if it fails, I suggest that you open a TAC case. Try turning off negotiation as well.

New Member

Re: Layer 3 3550 switch IOS Bug


I upgraded the switches and unfotunately the port did not come up.I had to downgrade back to 12.1(11)EA1 to get the port back up.

I suppose I will have to open a TAC case....

I could not turn of negotiation because the port is setup as a routed hop port.


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