6880-X Interfaces - GLC-T Speed and Duplex / int gig or int tengig

[Malcolm Booden]

Hi All,

I'm experienced with most of the Cisco LAN switching portfolio but had a question asked of me about setting speed and duplex on a 6880-X switch.  The customer is not using Instant Access clients, just the 6880-X chassis in VSS mode with a mix of fibre and copper SFP transceivers.

The customer has advised that they can't set the speed and duplex on a "tengig" interface and the port in question is a 100Mbps WAN link where the speed is negotiating 100Mbps / half duplex with the ISP's NTE with the SFP on the 6880-X being a GLC-T.

I don't have a 6880 in the lab so my question is, should the customer be able to change the speed and duplex if they go under gig 1/4 for example and entering the following.....

gigabitethernet 1/4

speed 100

duplex full

Is it the same on the 6880-X as an SFP+ port on a 3850 NM for example where you will see gig and tengig interfaces of the same physical interface number but you need to go under the gig or tengig interface depending on which transceiver is inserted?

I've searched everywhere for a show int status or a full show run from a 6880 on various forums etc to see if both gig and tengig interfaces are present or not but there is nothing that I have found to date.

If anyone with access to a 6880 could clarify this it would be appreciated.

Thanks

Malcolm

[Reza Sharifi]

Hi Malcolm,

You can't change the speed for GLC-T.  That is only a 1Gig interface.

HTH

[Malcolm Booden]

Hi Reza,

Thanks for the response, but it is only partially correct.

The GLC-T is gig capable but on certain platforms it can operate at 10/100/1000Mbps. 

"The 1000BASE-T SFP operates on standard Category 5 unshielded twisted-pair copper cabling of link lengths up to 100 m (328 ft). Cisco 1000BASE-T SFP modules support 10/100/1000 auto negotiation and Auto MDI/MDIX."

http://www.cisco.com/c/en/us/products/collateral/interfaces-modules/gigabit-ethernet-gbic-sfp-modules/product_data_sheet0900aecd8033f885.html

Please also see Cisco Live session BRKARC-3465 and page 109 of the attached PDF from the following link for the 6880 which indicates the platform supports these speeds with GLC-T.

https://www.ciscolive.com/online/connect/sessionDetail.ww?SESSION_ID=83439&backBtn=true

There is also several documents that outline the 6880 is capable of 10/100/1000Mbps but the customer has indicated the WAN link has auto-negotiated to 100Mbps half duplex and there is no option on the 6880 to set the speed and duplex manually with the speed 100 duplex / full commands.

I'm trying to ascertain if this can be done and if so is the gigabitethernet interface available or only tengigabitethernet even with GLC-T transceiver installed, but do not have one in the lab to test so was looking to see if anyone who has used a 6880-X could confirm?

It may be that only auto negotiate is available on the 6880-X and need to ask the ISP to change the speed and duplex manually on the NTE.

Thanks

Malcolm

[Reza Sharifi]

Hi Malcolm,

It could be that it can be enabled on certain model running certain IOS versions. I have tried this on couple of different platforms (6500, 4500) with no luck.

unfortunately, I don't have a 6880-X to test it for you.

Can you ask the customer to try turning off auto negotiation first and than speed and duplex command?

HTH

[Malcolm Booden]

Hi Reza,

Yes, it's platform specific as to the speeds that the GLC-T can operate at, but it's capable of 10/100/1000Mbps on several platforms.

I was trying to get a response and a show int status from someone with a 6880-X and GLC-T's in it before I went back to the customer though.

Thanks for your help anyway and I'll contact the customer for next steps.  Was hoping someone with a 6880-X could have checked before I went back to them but oh well!

Cheers

Malcolm

[Malcolm Booden]

Hi All,

I have an update on this after speaking to a Cisco SE.

It is actually a bug in certain software versions, where you can see the bug at the following location and software versions with known fixes.

https://tools.cisco.com/bugsearch/bug/CSCup92134

Regards

Malcolm