SENA PS210W - Manual (Page 39)

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configure the storage location for the system log or port data log of the If there is a firewall between
the Pro Series and the SYSLOG server, there must be a rule that allows all outgoing and incoming
UDP packets to travel across the Pro Series as the NFS server. For more information about the
configuration of the port/system log storage location, please refer to section, 4.2.8 Port Logging and
5.2 System Logging.
3.10. TCP service configuration
If a TCP session is established between two hosts, the connection should be closed (normally or
abnormally) by either of the hosts to prevent the lock-up of the corresponding TCP port. To prevent
this type of lock-up situation, the Pro Series provides a TCP “keep-alive” feature. The Pro Series will
send packets back and forth through the network periodically to confirm that the network exists . The
corresponding TCP session is closed automatically if there’s no response from the remote host.
To use the TCP “keep-alive” feature with the Pro Series, the users should configure three parameters
as follows:
 TCP keep-alive time:
This represents the time interval between the last data transmission and keep-alive packet
submissions by the Pro Series. These “keep-alive” messages are sent to the remote host to
confirm that the session is still open. The default time value is 15 sec.
 TCP “keep-alive” probes:
This represents how many “keep-alive” probes will be sent to the remote host, until it decides that
the connection is dead. Multiplied with the “TCP ‘keep-alive’interv als ”, this gives the time that a
link is forced to close after a “keep-alive” packet has been sent for the first time. The default is 3
times
 TCP keep-alive intervals:
This represents the waiting period until a “keep-alive” packet is retransmitted. The default value is
5 seconds.
By default, the Pro Series will send the keep-alive packets 3 times with 5 seconds interval after 15
seconds have elapsed since the time when there’s no data transmitted back and forth.
Figure 3-109 TCP keep-alive configuration