Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 612)

582 Multi-Service IronWare Switching Configuration Guide
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Master VLAN and member VLANs
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You can use topology groups with the following Layer 2 protocols:
• STP
• Foundry MRP
• VSRP
• RSTP
• Ethernet RIng Protection (ERP)
Master VLAN and member VLANs
Each topology group contains a master VLAN and can contain one or more member VLANs and
VLAN groups. A definition for each of these VLAN types follows:
• Master VLAN – The master VLAN contains the configuration information for the Layer 2
protocol. For example, if you plan to use the topology group for Foundry MRP, the topology
group’s master VLAN contains the ring configuration information.
• 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’s Layer 2 protocol configuration or Layer 2
topology affects all the member VLANs. Member VLANs do not independently run a Layer 2
protocol. VPLS VLANs can become member VLANs within a topology group.
• 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 1/1 and 1/2, a Layer 2 state change on port 1/1 applies
to port 1/1 in all the member VLANs that contain that port. However, the state change does not
affect port 1/1 in VLANs that are not members of the topology group.
Master VLANs and customer VLANs in Foundry MRP
A topology group enables you to control forwarding in multiple VLANs using a single instance of a
Layer 2 protocol such as Foundry MRP. For more information on topology group and Foundry MRP,
refer to the VLANs chapter.
Control ports and free ports
A port in a topology group can be a control port or a free port:
• A Control port is a port in the master VLAN and, therefore, is 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’s Layer 2 protocol. Each member VLAN must contain all of the control ports. All
other ports in the member VLAN are “free ports.”
• Free ports are not controlled by the master VLAN’s 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.