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4500X GLC-T at 100M


     Does anyone know how to configure a 4500X with a GLC-T SFP so that it will work at 100M.


The data sheets say it will work at 10/100/1000 but Im not seeing that happen

can't set the speed and it doesnt negotiate with anything at 100M

it will only work with auto to anoather switch set to auto and supports 1000M.


10 Replies 10

Reza Sharifi
Hall of Fame Expert Hall of Fame Expert
Hall of Fame Expert

According to the release notes, GLC-T is Gig.


1000BASE-T small form-factor pluggable module

See table-3 in this link:


the product spec sheets say 10/100/1000

is there no way to get copper 100M on a 4500X

Leo Laohoo
VIP Community Legend VIP Community Legend
VIP Community Legend

I believe GLC-T on a 4500X will only negotiate to 1 Gbps (like the 6500).

This is new product.  I only see Gig and 10Gig in the data sheet and no support for 100Mb.


I'm running into the same problem.   We have a copper link to an ISP whose policy it is to hard-code the hand-off to 100/full.  On the 4500x, the only option after the interface "speed" is nonegotiate.  And the output of "show int x capability" just shows speed of 1000.  This is unfortunate.

So it looks like my options are:

1.  hope the ISP can change to gig

2.  move the link to one of our access switches (but then we lose netflow capability)

By the way, when I look at the command reference guide for the release I'm running, the explanation is less than ideal. wrote:

2.  move the link to one of our access switches (but then we lose netflow capability)

Use a dedicated link/VLAN to connect to the access switch, and you will be able to use all the features.


Hi, did you ever get a resolution that worked i.e. the 4500-X with GLC-T to connect at 100Mbps? I have a customer who claims all of their sever and key hosts run at 1000BaseT and wish to deploy two new 4500-X in VSS mode, I know that some of the connects are 100BaseT so any feed back would be welcom

Etienne Simard
Cisco Employee
Cisco Employee

Release 15.2(3).E1 April 2015, adds this capability

LAN Switching Feature Review (IOS 15.2(3)E1) 

1. SDN


3. Bidi for 3850

4. XPS for 3850

5. GLC-T(100M/10M) and 100FX for 4500X


7. GRE


9. VRF Copy

10. LACP Rate Fast


I didn't find the information you specify Etienne, but when it comes to the 4500-X, it is possible to set the speed to 10/100Mbps since IOS-XE 3.7.1E.  



A limitation:  When you install the GLC-T (1000Base-T) SFP transceiver,  10/100 Mbps with auto negotiation is not supported.

In 3.8 IOS it appears autonegotiation does not occur after deleting speed setting from the config.

1. autonegotiation 1G/full working without any speed setting

2. set speed 100 or 10

3. no speed 100 or 10

Result: speed is retained at set 100 or 10 and autonegotiation back to 1G doesn't occur unless the switch is rebooted.

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