I have several Cisco Catalyst 3560 switches configured with multiple VLANs. Originally I was running IOS c3560-I9-mz.122-20.se4 and when I attached a Cisco 3550 switch in a basically unconfigured state to one of the access ports on the 3560, it would connect and act like it was a dumb hub or switch attached.
I just updated the Cisco 3560 switches to IOS c3560-ipbasek9-mz.122-53.SE. Now when I connect the 3550 switch to the 3560, I get the following on the console of the C3550:
00:08:04: %SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU on non trunk FastEthernet0/24 VLAN1.
00:08:04: %SPANTREE-7-BLOCK_PORT_TYPE: Blocking FastEthernet0/24 on VLAN0001. Inconsistent port type.
Using something like a cheap Netgear 16 port 10/100 switch does not do this and works just fine. However, I use the unconfigured 3550 switch as part of my traveling classroom setup and really need it to act as it did before so that I don't have to configure one of the ports as a trunk port and then chnage vlans on the switch each time I move to a new location with different vlans.
Any ideas on how I could do this?
I'll try the
Another option if this is used for training purposes is to turn off STP on vlan 1 on the 3550 ie.
no spanning-tree vlan 1
however you obviously need to be very careful if you do this ie. you could bring the network down.