Configuring A Vlan Group - Foundry Networks Switch and Router Installation And Configuration Manual

Configuring VLAN Groups and Virtual Interface Groups
To simplify configuration when you have many VLANs with the same configuration, you can configure VLAN
groups and virtual interface groups.
NOTE: VLAN groups are supported on the NetIron Internet Backbone router and BigIron Layer 3 Switches and
Layer 2 Switches with Management II or higher modules. Virtual interface groups are supported only on the
chassis-based 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 sub-net interface with all the VLANs in a group by
configuring a virtual 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. Since
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's 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.
NOTE: Alternatively, if your device uses a Management IV module, you can store and load the startup-
config file on the PCMCIA flash card. See "Loading the Startup-Config File from a PCMCIA Flash Card
During System Load" on page 5-30.
• The virtual interface group feature is useful when you want to configure the same IP sub-net address on all
the port-based VLANs within a VLAN group. You can configure a virtual interface group only after you
configure a VLAN group with the same ID. The virtual 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 interface groups. A virtual 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 interfaces. This is true regardless of whether you use
the virtual interface groups. To allocate additional memory, see "Allocating Memory for More VLANs or Virtual
Interfaces" on page 25-45.

Configuring a VLAN Group

To configure a VLAN group, use the following CLI method.
USING THE CLI
To configure a VLAN group, enter commands such as the following:
BigIron(config)# vlan-group 1 vlan 2 to 1000
BigIron(config-vlan-group-1)# tagged 1/1 to 1/2
The first command in this example begins configuration for VLAN group 1, and assigns VLANs 2 through 1000 to
the group. The second command adds ports 1/1 and 1/2 as tagged ports. Since all the VLANs in the group share
the ports, you must add the ports as tagged ports.
Syntax: vlan-group <num> vlan <vlan-id> to <vlan-id>
Syntax: tagged ethernet | pos <portnum> [to <portnum> | ethernet <portnum>]
The <num> parameter with the vlan-group command specifies the VLAN group ID and can be from 1 – 32. The
vlan <vlan-id> to <vlan-id> parameters specify a contiguous range (a range with no gaps) of individual VLAN IDs.
December 2000
Configuring Virtual LANs (VLANs)
25 - 43