nat session aging-time
Function
The nat session aging-time command sets the aging time of the NAT session table for each protocol.
The undo nat session aging-time command restores the default aging time of the NAT session table for each protocol.
For the default aging time of the NAT session table for each protocol, see Table 6-108.
Format
nat session protocol-name aging-time time-value
undo nat session { all | protocol-name } aging-time
Parameters
Parameter |
Description |
Value |
|---|---|---|
| protocol-name | Specifies the protocol type. |
The value can be dns, ftp, ftp-data, icmp, pptp, pptp-data, rtsp, rtsp-media, tcp and udp. |
time-value |
Specifies the aging time. |
The value is an integer that ranges from 1 to 65535, in seconds. |
| all | Restores the default aging times of the session tables for all protocols. |
- |
Usage Guidelines
Usage Scenario
You can run the nat session aging-time command to set the aging time of the protocol session table for each protocol. If an entry in a session table is not used within the specified period, the entry expires. For example, the user with the IP address 10.110.10.10 initiates a TCP connection through port 2000. If the TCP connection is not used within the timeout duration, the system deletes the TCP connection.
Table 6-108 lists the default aging time of the NAT session table for each protocol.
Protocol |
Default Aging Time |
|---|---|
dns |
120 seconds |
ftp |
120 seconds |
ftp-data |
120 seconds |
icmp |
20 seconds |
pptp |
600 seconds |
pptp-data |
600 seconds |
rtsp |
60 seconds |
rtsp-media |
120 seconds |
tcp |
600 seconds |
udp |
120 seconds |
Precautions
For some services such as the voice service, you must increase the TCP/UDP connection aging time to prevent service interruption.
