ISL Trunk Problem between a Cat2950 and a Cat5509

[rserao]

I'm trying to set up an ISL trunk between a cat5509 (datacenter) and a Cat2950 (perimter) via MM Fiber ports. I have 12 existing 2924 switches set up this way but can't get these 2950 to work.

OS on the 2950 is 12.05

OS on the 5509 is 4.5(8)

I have po 1/2 on the 5509 configured as a desirable ISL TR

I have int fa0/26 on the 2950 set up as an 802.1q tr with all VL allowed.

The VTP Server is the 5509 and the 2950 is set up as a client in the HHH domain.

I get a link light on both fiber ports.

The 2950 sees only VLAN1 the mgmnt vl, there are 24 actual VLs set up.

Can't ping it, and it can't ping anything else.

The RSM in the 5509 has the appropriate routes and interfaces setup.

I've run out of ideas as to why this isn't working. The same configuration works on the 2924 switch without any problems at all.

Any help would be appriecitated.

[Prashanth Krishnappa]

2950's support only dot1q trunking

http://cio.cisco.com/univercd/cc/td/doc/product/lan/cat2950/12111ea1/scg/swint.htm#xtocid5

[rserao]

Ok.. I read the link you posted.. Thanks... good info..

but.. how do I configure these things so that I get an isl trunk between them....

[rserao]

ok.. so it seems that the two fiber ports in the supIII module don't support dot1q either. When i swapped some fiber around and set po 4/1 to dot1q I got connected.

Thanks for pointing me in the right driection. My VAR Thanks you too cause now I have to buy another module for my 5509....

Have a good weekend....