Configuring Local Proxy ARP
To enable users who are isolated in the same bridge domain (BD) to communicate with each other, configure local proxy ARP.
Usage Scenario
In an EVC model, a BD is a broadcast domain, and member interfaces in a BD broadcast the packets they receive. To minimize broadcast traffic, split horizon can be configured on member interfaces that do not need to communicate with each other. After split horizon is enabled on member interfaces in a BD, users who are served by these interfaces are isolated. However, as services become more diverse and keep increasing, users have growing needs for intra-BD communication. To meet the service requirements, local proxy ARP can be configured on a VBDIF interface for member interfaces in a BD. (A VBDIF interface is a virtual interface.)
Assigning an IP address to a VBDIF Interface
The IP address assigned for a VBDIF interface that performs local proxy ARP for a bridge domain (BD) must be in the same network segment as the IP addresses of the member interfaces in the BD.
Procedure
- Run system-view
The system view is displayed.
- Run bridge-domain bd-id
A BD is created.
- Run interface vbdif bd-id
A VBDIF interface is created, and the VBDIF interface view is displayed.
The number of the VBDIF interface must be the same as the BD ID specified in Step 2.A VBDIF interface of a BD goes Up only if the BD has a Layer 2 sub-interface that is in the Up state. To add a Layer 2 sub-interface to a BD, run the bridge-domain (Layer 2 sub-interface view) command in the view of the Layer 2 sub-interface.
- Run ip address ip-address { mask | mask-length } [ sub ]
An IP address is assigned to the VBDIF interface.
- Run commit
The configuration is committed.
Enabling Local Proxy ARP
To allow isolated devices in a BD to communicate, enable the local proxy ARP function.
Procedure
- Run system-view
The system view is displayed.
- Run interface vbdif bd-id
The VBDIF interface view is displayed.
- Run arp-proxy local enable
Local proxy ARP is enabled.
After local proxy ARP is enabled, all the users in the BD can communicate. To enable intra-BD communications between only some member interfaces in the BD, run the undo split-horizon enable command on these interfaces instead of configuring the local proxy ARP function for the BD.
- Run commit
The configuration is committed.
