Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 394)

NOTE
Because virtual routing interfaces 2 and 3 do not have their own IP subnet addresses but instead are
"following" virtual routing interface a IP address, you still can configure an IPX or AppleTalk interface
on virtual routing interfaces 2 and 3.
VLAN groups and virtual routing interface group
To simplify configuration when you have many VLANs with the same configuration, you can configure
VLAN groups and virtual routing interface groups.
NOTE
VLAN groups are supported on Layer 3 Switches and Layer 2 Switches. Virtual routing interface
groups are supported only on Layer 3 Switches.
When you create a VLAN group, the VLAN parameters you configure for the group apply to all the
VLANs within the group. Additionally, you can easily associate the same IP subnet interface with all
the VLANs in a group by configuring a virtual routing interface group with the same ID as the VLAN
group.
• The VLAN group feature allows you to create multiple port-based VLANs with identical port
members. Because the member ports are shared by all the VLANs within the group, you must add
the ports as tagged ports. This feature not only simplifies VLAN configuration but also allows you to
have a large number of identically configured VLANs in a startup-config file on the device flash
memory module. Normally, a startup-config file with a large number of VLANs might not fit on the
flash memory module. By grouping the identically configured VLANs, you can conserve space in the
startup-config file so that it fits on the flash memory module.
• The virtual routing interface group feature is useful when you want to configure the same IP subnet
address on all the port-based VLANs within a VLAN group. You can configure a virtual routing
interface group only after you configure a VLAN group with the same ID. The virtual routing
interface group automatically applies to the VLANs in the VLAN group that has the same ID and
cannot be applied to other VLAN groups or to individual VLANs.
You can create up to 32 VLAN groups and 32 virtual routing interface groups. A virtual routing
interface group always applies only to the VLANs in the VLAN group with the same ID.
NOTE
Depending on the size of the VLAN ID range you want to use for the VLAN group, you might need to
allocate additional memory for VLANs. On Layer 3 Switches, if you allocate additional memory for
VLANs, you also need to allocate the same amount of memory for virtual routing interfaces. This is
true regardless of whether you use the virtual routing interface groups. To allocate additional memory,
refer to
Allocating memory for more VLANs or virtual routing interfaces on page 397.
Configuring a VLAN group
To configure a VLAN group, enter commands such as the following.
device(config)# vlan-group 1 vlan 2 to 257
device(config-vlan-group-1)# tagged 1/1 to 1/2
VLAN groups and virtual routing interface group
394 FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide
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