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.
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
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??