Chapter 3: Terminal Menu Operation and Structure
IP/Proxy ARP
Write security: 4; Read security: 5
This feature allows the network portion of a group of addresses to be shared between several physical network segments. The ARP protocol itself provides a way for devices to create a mapping between physical (i.e., Ethernet) ad- dresses and logical IP addresses. Proxy ARP makes use of this mapping fea- ture by instructing a router to answer ARP requests as a “proxy” for the IP addresses behind one of its ports. The device which sent the ARP request will then correctly assume that it can reach the requested IP address by sending packets to the physical address that was returned to it. This technique effec- tively hides the fact that a network has been (further) subnetted. If this option is set to Yes (def), when an ARP request is received on the Ethernet port the address is looked up in the IP routing table. If the forwarding port is not on the Ethernet port and the route is not the default route, the Express XL/XLT will answer the request with its own hardware address. If set to No, the Express XL/XLT will only respond to ARP requests received for its own IP address.
46 | Express XL/XLT User Manual |
