An asterisk on a port inside a vlan definition means, that this is the default vlan on that port, and untagged packets belong to that vlan.
Specifing more than one asterisk for the same port on different vlans is not useful, and I don't know what are the consequences of that. Maybe the whole vlan definition could be ignored, the possiblities are endless ;-)
Cisco equipment does not support a vlan 0, if you want to communicate with cisco hardware, do not use vlan 0.
If you don't communicate via a trunked port to cisco (or other) hardware, vlan numbers are inside your linux device only, and hence irrelevant to the cisco hardware.
If you want to have a trunked port, you should specify the letter "t" (for tagged) following the port number on the vlan definition.
The default is "t"agged for the cpu port (usually 5), and "u"ntagged for all other ports.
Since you did not specify "t" with vlan506, it would be not a trunked port, and your cisco hardware would never see any vlan information.
In my opinion, a trunked port should have an asterisk in exactly one vlan definition, and a "t" on the remaining vlan definitions.
Restrictions of VLAN 0 to 15 on a broadcom switch are correct, if you want shared/common vlans on both your router and a cisco device, stay within vlan1 to vlan15.
Additionally you should not use the default vlan as the management vlan on your cisco device (see cisco docs).
I hope this helps a little bit...
(Last edited by MMCM on 16 Apr 2008, 12:47)