we are occuring and problem when connecting an two existing toplogy based on Catalyst Cisco 2960 & 2950 and existing toplogie base on 3Com Switch 8810 Core switch that we need to connect them to gather.
When connect the 3com segment trought an access port on Vlan 10 to to Cisco catalyst on defaut Port Vlan 1 on catalyst 2960. The catalyst seen on error message :
%SPANTREE-2-RECV_1Q_NON_TRUNK: Received IEEE 802.1Q BPDU on non trunk
FastEthernet0/1 on vlan 1.
%SPANTREE-2-BLOCK_PORT_TYPE: Blocking FastEthernet0/1 on vlan 1.
Inconsistent port type.
After getting this error catalyst port used for this connexion stay in yellow color with non trafic passing.
Assuming that the catalyst switch port has a default configuration and there is another local Vlan used by another Catalyst port suching that Catalyst run PVST version.
when we connect to 3com switch to an access port vlan 10. and this switch run MSTP version, this configuration can cause this problem?
Please, what can you propose to resolve this issue?
You are connecting a switch (3Com) to an access port on Cisco switch(usually an access port is configured with spanning-tree portfast). This shouldn't be done especially if the BPDUguard is enabled.
You are getting the message because BPDUguard is detecting a BPDU packet on an Access port.
Try looking if you have bpduguard or bpdufilter enabled:
show run | i spanning-tree portfast bpduguard
show run | i spanning-tree portfast bpdufilter
If you have it configured, then there are 2 solutions:
1. configure trunking between 3Com and Cisco switch, and eliminate spanning-tree portfast
2. if you have no solution than connecting the 3Com on access port in switch, then on the Cisco port do:
spanning-tree bpduguard disable
spanning-tree bpdufilter disable
Let me know if this works for you!