problems with SPAN-port on catalyst 5500 and spanning-tree

[ilya_s]

I have following schema:

two catalyst 5500 from one side (up catalyst - primary, down catalyst - for redundancy) and two catalyst 5500 from other side (up catalyst - primary, down catalyst - for redundancy). They are connected among themselves (ring topology). All work fine (using spanning-tree protocol). At inclusion of SPAN-PORT on everyone cat5500 at reload the SPAN-PORT passes in a condition error-disable. SPAN-PORT connect to catalyst 2950. Why i error-disable status on cat5500 recived?

[Georg Pauwen]

Hello,

how is the port on the 2950 that is connected to the SPAN port on the 5500 configured ? Can you post the configuration of one of the 5500 switches and one of the 2950 switches ?

Regards,

Georg

[ilya_s]

cat 5500:

clear trunk 2/1 2-5

clear trunk 2/2 2-5

...

set trunk 2/1 on isl 1,6,7,8,1002-1005

set trunk 2/2 on isl 1,6,7,8,1002-1005

...

set vlan 6 7/1

set vlan 7 7/3

set vlan 7 7/2

set vlan 8 7/20

...

set trunk 7/20 off negotiate 1-1005

...

set span 1 7/20 both inpkts disable learning enable multicast disable create

2950 using config by default

5500-7/20-----2950-fa0/13

only add 1 span port on 2950:

monitor session 1 source interface Fa0/13 , Fa0/23

monitor session 1 destination interface Fa0/2

And sometimes may be port 7/20 go to error-disable status (sometimes - random times).