Configuration Guide User guide

ManualsBrandsBrocade ManualsComputer AccessoriesFastIron

841

842

843

844

845

846

847

848

849

850

790 FastIron Configuration Guide

53-1002494-02

IP subnet address on multiple port-based VLAN configuration

NOTE

If the Brocade device ARP table does not contain the requested host, the Brocade device

forwards the ARP request on Layer 2 to the same VLAN as the one that received the ARP

request. Then the device sends an ARP for the destination to the other VLANs that are using

the same IP subnet address.

• If the destination is in the same VLAN as the source, the Brocade device does not need to

perform a proxy ARP.

To configure multiple VLANs to use the same IP subnet address:

• Configure each VLAN, including adding tagged or untagged ports.

• Configure a separate virtual routing interface for each VLAN, but do not add an IP subnet

address to more than one of the virtual routing interfaces.

• Configure the virtual routing interfaces that do not have the IP subnet address to “follow” the

virtual routing interface that does have the address.

To configure the VLANs shown in Figure 85, you could enter the following commands.

Brocade(config)# vlan 1 by port

Brocade(config-vlan-1)# untagged ethernet 1/1

Brocade(config-vlan-1)# tagged ethernet 1/8

Brocade(config-vlan-1)# router-interface ve 1

Syntax: router-interface ve <number>

The commands above configure port-based VLAN 1. The VLAN has one untagged port (1/1) and a

tagged port (1/8). In this example, all three VLANs contain port 1/8 so the port must be tagged to

allow the port to be in multiple VLANs. You can configure VLANs to share a Layer 3 protocol

interface regardless of tagging. A combination of tagged and untagged ports is shown in this

example to demonstrate that sharing the interface does not change other VLAN features.

Notice that each VLAN still requires a unique virtual routing interface.

The following commands configure port-based VLANs 2 and 3.

Brocade(config-vlan-1)# vlan 2 by port

Brocade(config-vlan-2)# untagged ethernet 1/2

Brocade(config-vlan-2)# tagged ethernet 1/8

Brocade(config-vlan-2)# router-interface ve 2

Brocade(config-vlan-2)# vlan 3 by port

Brocade(config-vlan-3)# untagged ethernet 1/5 to 1/6

Brocade(config-vlan-3)# tagged ethernet 1/8

Brocade(config-vlan-3)# router-interface ve 3

The following commands configure an IP subnet address on virtual routing interface 1.

Brocade(config-vlan-3)# interface ve 1

Brocade(config-vif-1)# ip address 10.0.0.1/24

The following commands configure virtual routing interfaces 2 and 3 to “follow” the IP subnet