Proxy ARP
A type of ARP (Address Resolution Protocol) where the router acts as the ARP receiver and forward the MAC address of the router instead of the actual receiver.
For example, Host A wants to send data to ip 10.1.3.40. However, it needs to know the MAC address of 10.1.3.40 in order to construct layer 2 header.
It then broadcast the ARP (Address Resolution Protocol) request, the router when receive the ARP request, since it knows how to reach to 10.1.3.40, it will reply back to Host A its own mac address
Advantage:
- Simplify the network structure
This is default enabled in IOS (Cisco OS)
You can disable it using
no ip proxy-arp