We have some problems using our Catalyst 2950 switches, problems that may be generated by an incomplete VLAN configuration: If we configure a trunk port, all the frames the switch sends on that trunk have no VLAN tag, no matter what VLAN they are coming from. It is possible to change the configuration, to obtain properly tagged frames (if the configuration is the problem)?
Thanks in advance for any information.
This is the configuration (partial):
vtp mode transparent ! spanning-tree mode pvst no spanning-tree optimize bpdu transmission spanning-tree extend system-id vlan 12-14 ! interface FastEthernet0/5 ! interface FastEthernet0/6 switchport mode trunk switchport nonegotiate ! interface Vlan1 ip address 192.168.101.102 255.255.255.0 no ip route-cache
the result of show interface fa0/6 switchport: #sh interface fa0/6 switchport Name: Fa0/6 Switchport: Enabled Administrative Mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: dot1q Negotiation of Trunking: Off Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Voice VLAN: none Administrative private-vlan host-association: none Administrative private-vlan mapping: none Administrative private-vlan trunk native VLAN: none Administrative private-vlan trunk encapsulation: dot1q Administrative private-vlan trunk normal VLANs: none Administrative private-vlan trunk private VLANs: none Operational private-vlan: none Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2-1001 Capture Mode Disabled Capture VLANs Allowed: ALL
the result of show interface fa0/6 trunk: #sh interface fa0/6 trunk
Port Mode Encapsulation Status Native vlan Fa0/6 on 802.1q trunking 1
Port Vlans allowed on trunk Fa0/6 1-4094
Port Vlans allowed and active in management domain Fa0/6 1,12-14
Port Vlans in spanning tree forwarding state and not pruned Fa0/6 1,12-14