Sun Microsystems B1600, B100X, AND B100S manual Setting up a Tagged Vlan Trunk With Cisco Switches

6.4Setting up a Tagged VLAN Trunk With Cisco Switches

There is a known problem with setting a switch port to trunk mode if that port is connected to a port on a Cisco switch also in trunk mode (note that we use the word “trunk” in the sense of a point-to-point link, not in the sense of an aggregated link). This is because of a standardization issue (Cisco comply with the Cisco standard whereas the switch in the blade system chassis complies with the IEEE 802.1Q standard). It means that it will drop frames from the Cisco switch port’s native VLAN.

To work around this problem, you need to configure the system chassis’s switch port to hybrid (not trunk) mode, make sure that it has the same native VLAN Id as the Cisco switch, and also make sure that all the VLANs requiring connection to the Cisco switch have been added to the port. You must also stop packets for VLANs that the port is not a member of from entering the port.

Commands for a sample workaround are printed below. These assume a system chassis port (NETP0) with VLAN 1 as its native VLAN and hybrid as its link mode (this is the factory default configuration for the system chassis’s network ports).

The commands for the sample workaround also assume a Cisco switch port with trunk as itslink mode, VLAN 10 as its native VLAN, and additional membership of VLANs 11 and 12.

The commands for the workaround in this scenario are:

Console#configure

Console(config)#interface ethernet NETP0

Console(config-if)#switchport allowed vlan add 10

Console(config-if)#switchport native vlan 10

Console(config-if)#switchport allowed vlan remove 1

Console(config-if)#switchport allowed vlan add 11 tagged

Console(config-if)#switchport allowed vlan add 12 tagged

Console(config-if)#switchport ingress-filtering

Console(config-if)#end

Console(config)#

6-12Sun Fire™ B1600 Chassis and B100s, B100x, and B200x Blade Product Notes • May 2004