Gig port to SFP will only allow 100mb/s

[drewdown]

On the gig side I have to set the port speed to 100 to get it to come up. If I set it to Auto it won't come up, seems as though it can't negotiate the speed with the SFP. I have other switches connected in this fashion and their speed is 1000. 1 is a 10/100 3750 with 4 gig ports and the other is just a straigh gig 3750.

Any ideas?

 

[VinceWhirlwind]

What about the SFP - is it an FX?

 

[vipergg]

What kind of sfp is it ? Is it the 10/100/100 copper sfp ?
Please explain what connections you are using on each side and how the ports are configured. What kind of patch are you using . Also you must have 8 good wires in the complete path to run gig as gig uses all 8 wires to get gig speed..

 

[VinceWhirlwind]

It has to be the SFP - SFPs don't "negotiate" a speed.

 

[drewdown]

It should be a GLC-T but now that you said something about it I am assuming its not.

I will check on Monday and let you know.

 

[VinceWhirlwind]

Ah, well if it's a GLC-T, it *should* negotiate a speed, sorry...

The next likely suspect is the cable in that case - if all 4 pairs aren't there, the two sides will negotiate down to 100Mb.

 

[drewdown]

Definitely the cable. I tested with another gig 3750 and a GLC-T SFP. Wouldn't come up with a cat5 cable unless I set the speed on the gig switch to 100. Once I swapped it out with a cat6 it worked fine.

 

[vipergg]

You either had bad or missing pairs in the cable. Gig takes 8 good wires .

 

[burtsbees]

You need CAT6 for gig...

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!