Connection Timeout Settings - D-Link NetDefendOS User Manual

Chapter 13: Advanced Settings

13.5. Connection Timeout Settings

The settings in this section specify how long a connection can remain idle, that is to say with no
data being sent through it, before it is automatically closed. Please note that each connection
has two timeout values: one for each direction. A connection is closed if either of the two values
reaches 0.
TCP SYN Idle Lifetime
Specifies in seconds how long a TCP connection, that is not yet fully established, is allowed to
idle before being closed.
Default: 60
TCP Idle Lifetime
Specifies in seconds how long a fully established TCP connection may idle before being closed.
Connections become fully established once packets with their SYN flags off have travelled in
both directions.
Default: 262144
TCP FIN Idle Lifetime
Specifies in seconds how long a TCP connection about to close may idle before finally being
closed. Connections reach this state when a packet with its FIN flag on has passed in any
direction.
Default: 80
UDP Idle Lifetime
Specifies in seconds how long UDP connections may idle before being closed. This timeout value
is usually low, as UDP has no way of signaling when the connection is about to close.
Default: 130
UDP Bidirectional Keep-alive
This allows both sides to keep a UDP connection alive. The default is for NetDefendOS to mark a
connection as alive (not idle) every time data is sent from the side that opened the connection.
Connections that do not receive any data from the opening side within the UDP lifetime will
therefore be closed even if the other side continues to transmit data.
Default: Disabled
Ping Idle Lifetime
Specifies in seconds how long a Ping (ICMP ECHO) connection can remain idle before it is closed.
Default: 8
IGMP Idle Lifetime
862