3Com 10014299 Network Router User Manual


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