Full-duplex on Gigabit switching ports on a Cat4006

[pbanka]

I have a pair of Cat4006 switches in the datacenter that I just installed with the 48-port 10/100/1000 BASE-T blades. These things are beautiful!

A problem I'm having, though, is that I can't seem to set the ports into full-duplex gigabit mode. I can set them into full-duplex if they're running 100Base-TX just fine.

For example, do a "show run" and I see something like:

interface GigabitEthernet4/25

description RWC-DB-03-P

switchport access vlan 302

speed 1000

spanning-tree portfast

!

If I try to set it:

rwc-swc-i-3#conf t

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

rwc-swc-i-3(config)#int gig4/25

rwc-swc-i-3(config-if)#duplex full

Gigabit port is restricted to full duplex

rwc-swc-i-3(config-if)#exit

the running configuration doesn't show that it's full duplex. Also, if I do a "show int gig4/25", it seems to indicate that the port is in full duplex mode.

rwc-swc-i-3#sho int gig4/25

GigabitEthernet4/25 is up, line protocol is up (connected)

...

Full-duplex mode, link type is autonegotiation, media type is T

output flow-control is unsupported, input flow-control is unsupported, 1000Mb/s

input flow-control is off, output flow-control is off

Link type autonegotiation? What gives?

--Peter

[Prashanth Krishnappa · Accepted solution]

Gig interfaces are always full duplex.

2.7-4507-a(config)#interface gigabitEthernet 3/1

2.7-4507-a(config-if)#speed 1000

2.7-4507-a(config-if)#duplex full

Gigabit port is restricted to full duplex

2.7-4507-a(config-if)#speed 100

2.7-4507-a(config-if)#duplex full

2.7-4507-a(config-if)#speed 10

2.7-4507-a(config-if)#duplex half

2.7-4507-a(config-if)#

[chorethorious]

Peter if you don't mind the question. What type of 4006 do you have? I have a few of them on my network and I have only seen them with the Cat OS.. I.E. Set commands.. not the Native "conf t" commands. Please correct me if I am wrong.