System information

BSR 64000 Configuration and Management Guide
5-16
Address Resolution Using Proxy ARP
The router uses proxy ARP, as defined in RFC 1027, to help hosts with no knowledge
of routing determine the hardware addresses of hosts on the same or other networks or
subnets. Under proxy ARP, if the router receives an ARP request for a host that is not
on the same network as the ARP request sender, and if the router has the best route to
that host, the router sends an ARP reply packet giving its own local data link address.
In addition, if a host on the local network is incapable of responding to an ARP
request, the router responds on its behalf when Proxy ARP is enabled and host
IP-to-MAC address mapping is stored in the router with a static arp command
invoked with the alias option. The host that sent the ARP request then sends its
packets to the router, which forwards them to the intended host.
1. Proxy ARP is not enabled by default. To enable Proxy ARP, use the ip proxy-arp
command in Interface Configuration mode, as shown below:
MOT(config-if)#ip proxy-arp
2. To disable Proxy ARP, use the no ip proxy-arp command in Interface
Configuration mode, as shown below:
MOT(config-if)#no ip proxy-arp
3. To verify ARP status, use the show running-config command in Privileged
EXEC mode, as shown below:
MOT#show running-config
Configuring Broadcast Addressing
A broadcast is a data packet destined for all hosts on a particular physical network.
Network hosts recognize broadcasts by special addresses. The BSR system supports
the following broadcast packet types:
• Limited Broadcast - A packet is sent to a specific network or series of networks.
• Flooded Broadcast - A packet is sent to every network.
• Directed Broadcast - A packet is sent to a specific destination address where only
the host portion of the IP address is either all ones or all zeros.