cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
1617
Views
0
Helpful
40
Replies
Beginner

Re: Unable to connect to Core Switch

I have replicated the configuration in the lab with a 2950 as the access switch and a 3750 as a core switch and it works fine. This points to me that the config is ok (i stand corrected) and it must be something to do with physical connection. (maybe twin gig converters on core switch). My fear is splashing out on another twin gig converters as I initially thought it was a problem with SFP's got new ones and swapped them and it turned out it wasn't.

Contributor

Unable to connect to Core Switch

If your not getting link lights, its a layer 1 issue (if the ints are not shut).  What type of fiber are you using and sfps?

Have you tried rolling the fiber at one end?  Moving the tx and rx on one side.

Beginner

Re: Unable to connect to Core Switch

Hi Jimmy, the SFP's are GLC-SX-MM, initially used GLC-SX-MMD, however checked a Cisco doc that didn't list the SFP as compatible with a twin gig converter(X2) so got the former as a replacement. Swapped cables and all but nothing.

Sent from Cisco Technical Support iPhone App

Contributor

Unable to connect to Core Switch

Not swapping the cables, but rolling the fiber, there is a difference.

Are they directly connected or go through a patch panel?

Beginner

Re: Unable to connect to Core Switch

They go through a fibre patch panel but I have actually connected the devices directly eliminating the Fibre patch panel and still no connection.

Sent from Cisco Technical Support iPhone App

Contributor

Unable to connect to Core Switch

Ok, someone else will have to take the helm here as its Saturday morning and I am heading out to take the woman for her errands. They use the LC type connector and they were directly connected using the same cable, its not a rolling issue (or I have never seen this, normally that cable is rolled already.  The cool thing about problems like this is learn so much along the way!  I wish you luck.

Beginner

Re: Unable to connect to Core Switch

Are you using a single mode or multi mode fiber patches?

Highlighted
Beginner

Re: Unable to connect to Core Switch

Hi Dragos,

Its Mulitmode.

I will get new cables and try again on monday just in case.. The cables are LC-LC i believe. Will check and confirm.

Thank you so much for your help Dragos and Jimmy, its really appreciated. I am not that versed in fibre cabling but will get someone who is to help check.

Beginner

Re: Unable to connect to Core Switch

Hi folks,

Just wanted to let you know the issue has been resolved by issuing

Switch(config)# hw-module module m port-group p

select gigabitethernet

this makes the supervisor engine use the gigabit Ethernet (if chosen) instead of the ten gigabit port.

Stumbled on this while going through some Cisco documentation. Also had to configure int gig5/3 & 4 instead of int tengig5/1( as configured original, see posted config)

Many thanks to Dragos, janko and jimmy. I appreciate your help.

Sent from Cisco Technical Support iPhone App

Sent from Cisco Technical Support iPhone App

Beginner

Re: Unable to connect to Core Switch

Hy Abayomi,

Thanks for  the solution. i was really curious about the problem.

Best regards,

Dragos Tudor

Contributor

Re: Unable to connect to Core Switch

Glad to hear, admittedly I would not of got the solution you arrived at, congrats and nice job!!  Thanks for the update, I will file that solution away in the memory banks!

CreatePlease to create content
Content for Community-Ad
July's Community Spotlight Awards