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Catalyst WS-C3550-12T not able to set Gigabit-speed explicitly

I'm not able to set Portspeed to Gigabit, only auto is possible

dcdwx101/#conf term

Enter configuration commands, one per line. End with CNTL/Z.

dcdwx101/(config)#int gi0/1

dcdwx101/(config-if)#speed ?

10 Force 10 Mbps operation

100 Force 100 Mbps operation

auto Enable AUTO speed configuration


Is that by design ? Or problem of IOS-Version ?

dcdwx101/#sh vers

Cisco Internetwork Operating System Software

IOS (tm) C3550 Software (C3550-I5Q3L2-M), Version 12.1(4)EA1e, RELEASE SOFTWARE


Copyright (c) 1986-2001 by cisco Systems, Inc.

Compiled Thu 06-Sep-01 17:49 by antonino

Image text-base: 0x00003000, data-base: 0x005F2E90

ROM: Bootstrap program is C3550 boot loader

dcdwx101/ uptime is 1 year, 16 weeks, 4 days, 14 hours, 58 minutes

System returned to ROM by power-on

System restarted at 16:21:40 UTC Wed Feb 27 2002

System image file is "flash:c3550-i5q3l2-mz.121-4.EA1e/c3550-i5q3l2-mz.121-4.EA1


cisco WS-C3550-12T (PowerPC) processor (revision B0) with 65526K/8192K bytes of


Processor board ID FAA0548T031

Last reset from warm-reset

Bridging software.

Running Layer2/3 Switching Image

Ethernet-controller 1 has 1 Gigabit Ethernet/IEEE 802.3 interfaces



Ethernet-controller 12 has 1 Gigabit Ethernet/IEEE 802.3 interfaces

12 Gigabit Ethernet/IEEE 802.3 interface(s)

32K bytes of flash-simulated non-volatile configuration memory.

Base ethernet MAC Address: 00:08:21:2B:4A:80

Motherboard assembly number: 73-5527-10

Power supply part number: 34-0967-01

Motherboard serial number: FAA0545IXE5

Power supply serial number: LIT051100B6

Model revision number: B0

Model number: WS-C3550-12T

System serial number: FAA0548T031

Configuration register is 0x10F

Thank you



Re: Catalyst WS-C3550-12T not able to set Gigabit-speed explicit

It's by design, no problem with IOS.

Please take a look at

In this document, you can read about 'speed' command:

"speed {10 | 100 | auto}

Gigabit Ethernet ports can be configured to run at 10, 100, 1000 Mbps. To set a Gigabit Ethernet port to 1000 Mbps, set both ends of the link to 'auto'. "