ADTRAN L128 - Manual (Page 63)

Chapter 3: Terminal Menu Operation and Structure
46 Express L128/L128T User Manual 61202.070L1-1
UDP Relay List/UDP Port 1, UDP Port 2, UDP Port 3
Write security: 3; Read security: 5
UDP Port 1, UDP Port 2, and UDP Port 3 are used for specifying UDP ports to
be relayed. These fields only apply when UDP Port Type is set to Specified.
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 L128/L128T
will answer the request with its own hardware address. If set to No, the Ex-
press L128/L128T will only respond to ARP requests received for its own IP
address.