38 ServerIron ADX Security Guide
53-1002440-03
Traffic segmentation
1
Considerations when configuring VLAN bridging
The following considerations apply when configuring VLAN bridging:
Up to 64 unique-pair VLAN bridges can be configured.
A VLAN cannot be part of two different VLAN bridges.
Two VLANs forming a bridge must have the same set of member ports on the ServerIron ADX
where they are joined.
The Control VLAN (4094) and system default VLAN cannot be used for VLAN bridging.
The hot-standby scenario is the only High Availability configuration supported with VLAN
bridging. In a hot-standby scenario with one-armed topology, after fail over, the existing session
may not be continued if the Layer-2 Switch in the middle cannot learn the MAC address of the
Gateway through the newly-active ServerIron ADX in time.
VLAN bridging is only supported with switch code. It is not supported with the ServerIron ADX
router code.
VLAN bridging is not supported with the SYN-proxy feature.
All ports within a VLAN bridge must be tagged members of a VLAN and its associated bridged
VLAN.
MAC learning is shared for VLANs that are bridged together.
Configuring VLAN bridging
The vlan-bridge command is used to configure VLAN bridging. To configure VLAN 10 and VLAN 12
for VLAN brid ging, use th e following co mmand.
ServerIron(config)# vlan-bridge 10 12
Syntax: [no] vlan-bridge <VLAN-number> <VLAN-number>
The <VLAN-number> variables specify the pair of VLANs that you want to create VLAN bridging for.
Layer-2
Switch
Gateway
ServerIron ADX
(active)
Vlan 2 Vlan 3 Vlan 4
Domain1 Domain2 Domain3
Vlan -Bridging
2-12, 3-13, 4-14
Vlans
2, 3, 4, 12, 13, 14
Vlans
12, 13, 14
Vlans
2, 3, 4, 12, 13, 14
Vlan -Bridging
2-12, 3-13, 4-14
ServerIron ADX
(standby)