3Com 10014299 manual Configure the Internal Server, Configure the Timeout of address translation

Configure Network Address Translation (NAT) 353

corresponding internal server. During the course of address translation, it will look up the resource address of the message, to determine if the message is sent from the internal server. If yes, the source address is translated to the corresponding public network address.

The information the user needs to configure includes: external address, external port, external server address and the type of internal server port and protocol.

Please carry out the following configuration under interface view.

Table 386 Configure the Internal Server

Operation	Command
Add one internal server	nat server global global-addr { global-port
	any domain ftp pop2 pop3 smtp telnet
	www } inside inside-addr { inside-port any
	domain ftp pop2 pop3 smtp telnet www
	} { protocol-number ip icmp tcp udp }
Delete one internal server	undo nat server { global inside } address {
	port any domain ftp pop2 pop3 smtp
	telnet www } { protocol-number ip icmp
	tcp udp }

inside-port is indispensable, ranging 1 to 65535.

If global-port is not defined, its value equals to that of inside-port.

When deleting one internal server, if the global key word is used, then the external address, port and protocol information also need to be provided; If inside key word is used, only the internal address and port number need to be provided.

The protocol can be TCP, UDP, IP or ICMP.

5Configure the Timeout of address translation

As the HASH table used in the address translation can't be saved permanently, the user can set up the Timeout of address translation for TCP, UDP and ICMP protocol. If this address is not used for translation within the time set up, the system will delete the link.

Please process the following configurations in the system view.

Table 387 Configure the Timeout of address translation

Operation	Command
Configure the Timeouts of NAT	nat	aging-time	{ tcp udp
	icmp } seconds
Restore the default value of the Timeout of address	nat	aging-time	default
translation

By default, the Timeout for TCP address translation is 240 seconds and 40 seconds for UDP address translation.

The Timeout for ICMP address translation is 20 seconds.