02-29-2008 08:40 AM - edited 03-05-2019 09:28 PM
Hi ...
I have a problem which I just cannot work out, I have 2 x 6509's with GBIC modules in - they are currently running CATOS.
I have successfully (and easily !) setup trunk links between them and numerous 3500 switches (also with GBICs). The trouble is I cannot get a 3560g to connect directly via a trunk link and fibre (using the minigbics), is there an incompatibility problem or is it just me.
I have tried a couple of different 3560g's also change dall patch leads etc. - I can get them to connect using fibre/rj45 convertors but I wanted to use gbics both ends.
What am I doing wrong?
thanks
Andrew
02-29-2008 08:50 AM
Hi,
The encapsulation type (802.1q or isl) is the same to both end?
For reference:
http://www.cisco.com/en/US/tech/tk389/tk689/technologies_configuration_example09186a0080094784.shtml
http://www.cisco.com/en/US/tech/tk389/tk689/technologies_configuration_example09186a008009441a.shtml
I hope this helps.
Best regards.
Massimiliano.
02-29-2008 11:31 AM
Hi Massimiliano,
yes both ends are set for dot1q - as soon as I replace the 3560g and put in an old 3550xl it works fine...very strange
many thanks
Andrew
03-02-2008 07:59 PM
Hello,
I am not sure this will help so flame me if it doesn't. The 3550's default DTP setting is âswitchport mode dynamic desirableâ and the 3560's default DTP setting is âswitchport mode dynamic autoâ.
This means that a default 3550 port will create a trunk when connected to any other port except one that is configured as a access port (âswitchport mode accessâ - no trunking). A default 3560 port will create a trunk when connected to any other port except one that is configured as a access port OR a port configured as âswitchport mode dynamic auto.â
Nick.
03-02-2008 11:35 PM
Hi,
Try this option on trunk links....n let us know..
int gig x/x
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
HTH, Pls rate if it helps..
*aijaz*
03-03-2008 03:02 AM
Hi ..
thanks to all those who have replied, unfortunately still no luck.
I have changed both ends from on/desireable/auto step by step and now have enclosed my current config (I have just changed the patch leads again for good
measure!).
Thanks for the info Nick on the default settings - I didnt know that had changed.
thanks
Andrew
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