User's Manual

Table Of Contents
393
Users Manual of CS-6306R
Activating proxy ARP
The system uses the proxy ARP (defined by RFC 1027) to obtain the host’s MAC address on other networks
for the hosts without corresponding routes. For example, when the routing switch receives an ARP request
and finds that the source host and the destination host are not connected to the same interface and all the
routes that the routing switch reaches the destination host are not through the interface that receives the ARP
request, it will send a proxy ARP response that contains its address of the link layer. The source host then
sends the message to the routing switch and the switch forwards it to the destination host. The proxy ARP is
activates by default.
To activate the proxy ARP, run the following command in interface configuration mode:
Run… To
ip proxy-arp
Activate the proxy ARP on the
interface.
Configuring free ARP function
The switch can know whether the IP addresses of other devices collide with its IP address by sending free
ARP message. The source IP address and the destination IP address contained by free ARP message are
both the local address of the switch. The source MAC address of the message is the local MAC address.
The switch processes free ARP message by default. When the switch receives free ARP message from a
device and finds that the IP address contained in the message collide with its own IP address, it will return an
ARP answer to the device, informing the device that the IP addresses collide with each other. At the same
time, the switch will inform users by logs that IP addresses collide.
The switchs function to send free ARP message is disabled by default. Run the following commands to
configure the free ARP function on the port of the switch:
Run… To
arp send-gratuitous
Start up free ARP message
transmission on the interface.
arp send-gratuitous intervalvalue
Set the interval for sending free ARP
message on the interface.
The default value is 120 seconds.
2. Mapping host name to IP addres
Any IP address can correspond to a host name. The system stores a hostname-to-address mapping cache
that you can telnet or ping.
Run the following command in global configuration mode to specify a mapping between host name and IP
address:
Run… To
ip hostname address
Statically map the host name to the IP
address.