Brocade TurboIron 24X Series Configuration Guide - Manual (Page 308)

274 Brocade TurboIron 24X Series Configuration Guide
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Topology groups
• Member VLANs – The member VLANs are additional VLANs that share ports with the master
VLAN. The Layer 2 protocol settings for the ports in the master VLAN apply to the same ports in
the member VLANs. A change to the master VLAN Layer 2 protocol configuration or Layer 2
topology affects all the member VLANs. Member VLANs do not independently run a Layer 2
protocol.
• Member VLAN groups – A VLAN group is a named set of VLANs. The VLANs within a VLAN
group have the same ports and use the same values for other VLAN parameters.
When a Layer 2 topology change occurs on a port in the master VLAN, the same change is applied
to that port in all the member VLANs that contain the port. For example, if you configure a topology
group whose master VLAN contains ports 1 and 2, a Layer 2 state change on port 1 applies to port
1 in all the member VLANs that contain that port. However, the state change does not affect port 1
in VLANs that are not members of the topology group.
Control ports and free ports
A port that is in a topology group can be a control port or a free port:
• Control port – A control port is a port in the master VLAN, and is therefore controlled by the
Layer 2 protocol configured in the master VLAN. The same port in all the member VLANs is
controlled by the master VLAN Layer 2 protocol. Each member VLAN must contain all of the
control ports and can contain additional ports.
• Free port – A free port is not controlled by the master VLAN Layer 2 protocol. The master VLAN
can contain free ports. (In this case, the Layer 2 protocol is disabled on those ports.) In
addition, any ports in the member VLANs that are not also in the master VLAN are free ports.
NOTE
Since free ports are not controlled by the master port Layer 2 protocol, they are assumed to
always be in the Forwarding state.
Configuration considerations
• Topology groups are supported.
• You must configure the master VLAN and member VLANs or member VLAN groups before you
configure the topology group.
• You can configure up to 256 topology groups. Each group can control up to 4096 VLANs. A
VLAN cannot be controlled by more than one topology group.
• The topology group must contain a master VLAN and can also contain individual member
VLANs, VLAN groups, or a combination of individual member VLANs and VLAN groups.
• If you add a new master VLAN to a topology group that already has a master VLAN, the new
master VLAN replaces the older master VLAN. All member VLANs and VLAN groups follow the
Layer 2 protocol settings of the new master VLAN.
• If you remove the master VLAN (by entering no master-vlan ), the software selects the
new master VLAN from member VLANs. A new candidate master-vlan will be in configured
order to a member VLAN so that the first added membe VLAN will be a new candidate master
VLAN. Once you saved and reloaded, a member VLAN with the newest VLAN ID will be the new
candidate master. The new master VLAN inherits the Layer 2 protocol settings of the older
master VLAN.