Cabletron Systems HSIM-W6 manual Enabling Proxy ARP on a Port

Chapter 7: General Configuration Using Local Management

The UDP Broadcast Redirector enables you to configure any Routing Services enabled device to forward the UDP packets that it receives as LAN broadcasts, directly to the appropriate server. UDP service requests that are sent as LAN broadcasts by clients of applications such as Host Name, Domain Name, and Bootstrap servers, can be redirected to any server on any network segment.

To configure the UDP Broadcast Redirector, complete the following steps:

1.Use the arrow keys to highlight the UDP Port field under System Level Setup.

2.ENTER the UDP port number of the UDP service request packets that you want to redirect (refer to Table 23) and then press ENTER.

3.Use the arrow keys to highlight the SAVE command at the bottom of the screen and then press ENTER. The message “SAVED OK” displays.

NOTE

You can type in the UDP port number, or you can use the +REDIRECTOR- command at the bottom of the screen to scroll through a list of commonly used UDP port numbers. To use the +REDIRECTOR- command, use the arrow keys to highlight the + (to go forward), or the - (to go backward), and then press the ENTER key to scroll in the direction that you selected.

The entry for the UDP Port field reflects the UDP port number that is currently selected. The entry for UDP Type names the UDP service to which that port number corresponds.

Enabling Proxy ARP on a Port

By default, Proxy Address Resolution Protocol (ARP) is disabled on all ports, and IP Routing Services respond only to ARP requests addressed to its own IP address.

In order for one IP host to communicate with another IP host, the target host’s MAC address must be known. To learn this MAC address, the IP host sends an ARP request packet as a LAN broadcast with the destination IP address of the target IP host. All hosts receive this broadcast and the one host that matches the target IP address responds with its MAC-layer address. However, because each subnet constitutes a separate broadcast domain and LAN broadcasts are not forwarded across routers, ARP does not work beyond a host’s local network or subnetwork. One of the primary purposes of a router is to confine LAN broadcast traffic to each local network or subnetwork.

HSIM-W6 User’s Guide 149