Proxy ARP is the technique in which a router answers ARP requests intended for another node. The router appears to be present on the same network as the ‟real” node that is the target of the ARP and takes responsibility for routing packets to the ‟real” destination. Proxy ARP can help nodes on a subnet reach remote subnets without configuring routing or a default gateway.
Typical routers only support proxy ARP for directly attached networks; the router is targeted to support proxy ARP for all known networks in the routing instance where the virtual interface proxy ARP is configured.
To support DSLAM and other edge-like environments, proxy ARP supports policies that allow the provider to configure prefix lists that determine for which target networks proxy ARP is attempted and prefix lists that determine for which source hosts proxy ARP is attempted.
Also, the proxy ARP implementation supports the ability to respond for other hosts within the local subnet domain. This is needed in environments such as DSL where multiple hosts are in the same subnet but cannot reach each other directly.
Static ARP is used when a Nokia router needs to know about a device on an interface that cannot or does not respond to ARP requests. The configuration can state that, if it has a packet with a specific IP address, to send it to the corresponding ARP address. Use proxy ARP so the router responds to ARP requests on behalf of another device.