Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) User Manual
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Brocade Virtual ADX Switch and Router Guide
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Configuring the same IP subnet address on multiple port-based VLANs
3
NOTE
If the Brocade device’s 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
, you could enter the following commands.
Virtual ADX(config)# vlan 1 by port
Virtual ADX(config-vlan-1)# untag ethernet 1/1
Virtual ADX(config-vlan-1)# tag ethernet 1/8
Virtual ADX(config-vlan-1)# router-interface ve 1
Syntax: ip follow ve num
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.
Virtual ADX(config-vlan-1)# vlan 2 by port
Virtual ADX(config-vlan-2)# untag ethernet 1/2
Virtual ADX(config-vlan-2)# tag ethernet 1/8
Virtual ADX(config-vlan-2)# router-interface ve 2
Virtual ADX(config-vlan-2)# vlan 3 by port
Virtual ADX(config-vlan-3)# untag ethernet 1/5 to 1/6
Virtual ADX(config-vlan-3)# tag ethernet 1/8
Virtual ADX(config-vlan-3)# router-interface ve 3
The following commands configure an IP subnet address on virtual routing interface 1.
Virtual ADX(config-vlan-3)# interface ve 1
Virtual ADX(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
address configured on virtual routing interface 1.
Virtual ADX(config-vif-1)# interface ve 2
Virtual ADX(config-vif-2)# ip follow ve 1
Virtual ADX(config-vif-2)# interface ve 3
Virtual ADX(config-vif-3)# ip follow ve 1