09-28-2017 12:52 PM - edited 03-08-2019 12:12 PM
i have a 2960x that has this configurations ONLY i mean i haven't even added a host name
VTP mode off
spanning-tree mode rapid-pvst
spanning-tree vlan 1 root secondry
interface vlan 1
ip add 10.1.1.2 255.255.255.0
----------------------------------------------------
and that is it
i also have a 3850 with this configuration:
vtp mode off
spanning-tree mode rapid-pvst
spanning-tree vlan 1 root primary
interface vlan 1
ip adderss 10.1.1.1 255.255.255.0
interface gig 1/0/1
sw mode trunk
----------------------------------------------
and thats it no more configuration
now when i connect my 3850 port 1 to ports 1-48 on my 2960x i have a fully functional trunking between them and i can ping but if i connect my 3850 to ports 49 and 50 on 2960 witch are sfp+ ports with cisco glc-t connected to them i cannot make trunking work and every thing fails and i dont know what the **bleep** is going on
i have checked every thing
please help me i am pulling my hair right now
you also should know i have 7 other 2960x the same one that are working correctly but i have configured them all but this one had issues then and i couldn't fix it so i have erased my switch and now you know what is going on.
please help
09-28-2017 01:13 PM
If the 2960x does not work with GLC-T, can you try connecting it to the 3850 using fiber?
HTH
09-29-2017 05:44 AM
1- i have 6 other 2960x the same model that are working with glc-t sfp modules
2- i have 6 other 2960x the same model that i have configured this way and are worknig correctly but this one even if i configure it wont work
3- 2960 runs : 15.2(2)E6 and 3850 runs : 03.06.05E
thank you all but i have tryed all of them and still i don't know why this is hapening on this switch if you want i can give you access to them
09-29-2017 07:53 AM
Have you tried the suggestions? I understand that you have other switches that are configured the same and the configuration is working fine there. What we're saying is the "auto" part might not be functioning right on this switch which could happen. It's typically a best practice to hard code your trunk links as trunks to save some time and bring the links up faster without having to do DTP.
09-28-2017 01:25 PM
09-28-2017 01:29 PM
09-28-2017 01:31 PM
Greetings,
Could you tell us what software versions you are running on the switches?
Also, DTP sometimes fails for a variety of reasons. Did you try setting the ports to trunk manually?
Swx3850(config)#int gig 1/0/1 Swx3850(config-if)#sw mode trunk Swx3850(config-if)#sw trunk noneg ... Swx2960(config)#int gig 1/0/49 Swx2960(config-if)#sw mode trunk Swx2960(config-if)#sw trunk noneg
09-29-2017 06:35 AM
Hi
As it was mentioned previously, you can disable the negotiation or try with speed auto.
09-29-2017 07:40 AM
On a side note, I have looked around and it seems that there is a bug with certain IOS versions where the switch does not recognise the SFPs. When you do a 'show inventory' do you actually see them listed ?
Either way, the recommended fix is to downgrade the IOS to 15.0(2)EX3.
09-29-2017 10:18 AM
thank you guys but after manually configuring the trunk port nothing has changed and even a downgrade didn't help if any of you guys want I can give you all a remote access to both switches to check em out
09-29-2017 10:19 AM
thank you guys but after manually configuring the trunk port nothing has changed and even a downgrade didn't help
10-02-2017 02:40 AM
come on guys please help me I don't know what else to do
10-02-2017 03:52 AM - edited 10-02-2017 04:11 AM
Hi
On the Switches 4948 you must specify the type of media, try to use this command on the 3850 or 2960x:
interface gx/x/x
metry-type <select the media>
or
try the following
configuring auto the negotiation
conf t
default interface g1/1/1
interface g1/1/1
switchport mode trunk
speed auto
duplex auto
no shutdown
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