Configuring Routed Proxy ARP
Routed proxy ARP allows devices that have IP addresses on the same network segment but different physical networks to communicate with each other.
Usage Scenario
A large company network is usually divided into multiple subnets to facilitate management. The routing information of a host in a subnet can be modified so that IP datagrams sent from this host to another subnet are first sent to the gateway and then to another subnet. However, this solution makes it hard to manage and maintain devices. Deploying proxy ARP on the gateway effectively resolves management and maintenance problems caused by network division.
Pre-configuration Tasks
Before configuring routed proxy ARP, complete the following tasks:
Configure physical parameters for interfaces to ensure that the physical status of the interfaces is Up.
Configure link layer protocol parameters for interfaces to ensure that the link layer protocol status of the interfaces is Up.
Configuring an IP Addresses for an Interface
The IP address assigned to a routed proxy ARP-enabled interface must be on the same network segment with the IP address of the host on the LAN to which this interface connects.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number [ .subinterface-number ] interface-number
The interface view is displayed.
- Run ip address ip-address { mask | mask-length } [ sub ]
An IP address is configured for the interface.
- Run commit
The configuration is committed.
Enabling Routed Proxy ARP
To allow subnets on the same IP network to communicate, enable routed proxy ARP.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number [ .subinterface-number ]
The interface view is displayed.
- Run arp-proxy enable
Routed proxy ARP is enabled on the interface.
After routed proxy ARP is enabled, you must reduce the aging time of ARP entries on the device so that the number of packets received but cannot be forwarded by the device is decreased.
- Run commit
The configuration is committed.
Verifying the Configuration of Routed Proxy ARP
After configuring routed proxy ARP, verify the configuration.
Procedure
- Run the display arp interface interface-name command to check the ARP mapping table on a specified interface.
- Run the display arp slot slot-id command to check the ARP mapping table on the board in a specified slot.
- Run the display arp vpn-instance vpn-instance-name slot slot-id [ dynamic | static ] command to check the ARP mapping table for a specified VPN instance.
