Netvanta 1638 trunk to cisco 2960x causes lose of internet connection

[mogulsurf]

I have 2 netvanta1638 switches from windstream   vlan 160 (data)   vlan 200 (phones)

I recently purchased a new cisco 2960x switch..

I created a trunk port on the cisco and a trunk port on the netvanta

everytime i connect the 2 trunk ports ..,my users complaint that they lose connecton.

I verified this with a ping -t 8.8.8.8 and each time I connect the new cisco switch..i lose connection

anyone have any idea why this is ?

There are no ip assigned to the cisco only vlan 160 vlan 200

I originally assinged ip to vlan 1 for managnement thought this was the problem so I took it out...

all ports are still unassigned expect for port 48 which is the trunk port..

Im connecting this from my desk ==> wall plate ===> patchpanel ====> to the trunk port on the netvanta switch

[Anonymous]

I sometime run into issues with BPDU when connecting Adtran switches to Cisco devices.  Try enabling bpdu filter on the port that links to the Cisco.

It may help.

[mogulsurf]

Thank you for the response...

It seems like the issue that was causing the problem was STP.

The cisco switch was trying to become th Root bridge.

I manualy set the Root bridge to 40960 and let the Adtran 4096 maintain as the root bridge.

adtran and the cisco are usint Rapid pvst.

i have 3 vlan's

vlan1

vlan160

vlan200

in vlan1 it seems to be working properly

however in vlan 160 and vlan 200

i see both the Adtran (bridge id 4096) as the root bridge and the cisco is also showing it self as the root bridge (bridge id 40960+160=41120)

how can there be 2 root bridge for the same vlan??