Port down when i force in speed 100

Hi,

I have a Cisco 3560. I must plug a XLAN link on a port. This port must be forced at 100Mb full duplex to enable the connexion.

When i forced the port, the interface become down...

Why?

If i let the config in auto negociation, the switch negociate a half duplex and i have missmatch duplex error.

Here, the configuration of this interface :

interface GigabitEthernet0/24 description Vers le XLAN switchport trunk allowed vlan 60,63,65-68 speed 100 duplex full !

here, the show version :

Cisco IOS Software, C3560 Software (C3560-IPSERVICES-M), Version

ROM: Bootstrap program is C3560 boot loader BOOTLDR: C3560 Boot Loader (C3560-HBOOT-M) Version 12.2(25r)SEE4, RELEASE SOFTWARE (fc1)

TR-3560-HDV-3-1 uptime is 53 minutes System returned to ROM by power-on System image file is "flash:c3560-ipservices-mz.122-25.SEE3/c3560- ipservices-mz.122-25.SEE3.bin"

cisco WS-C3560G-24PS (PowerPC405) processor (revision F0) with 118784K/

12280K bytes of memory. Processor board ID FOC1034Y24L Last reset from power-on 7 Virtual Ethernet interfaces 28 Gigabit Ethernet interfaces The password-recovery mechanism is enabled.

The problem come from the duplex and the speed. The interface become down when i use this command : speed 100 duplex full

And not when i type the trunk command. When i withdraw trunk commands, and i use speed 100 and duplex full, the interface stay down.

i use cross over cable. And this cable works fine with my 3750 switch actual. I want to replace it by this 3560.

Thx a lot for your help.

Best regards, Olivier Legras