Cyclades AlterPath ACS, Command Reference Manual

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AlterPath ACS Command Reference Guide
119
Network
4.8 TCP Keepalive
The objective of this feature is to allow the ACS to recognize when the socket client
(SSH or Telnet) goes down without closing the connection properly. Currently, if this
happens in a serial port the system administrator must close the connection manually or
nobody else can access that port anymore.
How it works
The TCP engine of ACS will send a tcp keepalive message (ACK) to the client. If the
maximum retry number is reached without an answer from the client, the connection is
closed.
VI mode
The configuration is done in the file /bin/init_proc_fs using the linux proc filesystem.
CLI Method - TCP Keep Alive
Step 1 - .Open the CLI interface by issuing the command:
# CLI
# Enable TCP keepalive timer in ACS (six retries with ten seconds
# of interval from each other).
# keepalive interval when the client is answering
echo 20 > /proc/sys/net/ipv4/tcp_keepalive_time
# keepalive interval when the client is not answering.
echo 10 > /proc/sys/net/ipv4/tcp_keepalive_intvl
# number of retries
echo 6 > /proc/sys/net/ipv4/tcp_keepalive_probes
# Enable TCP keepalive timer (six retries with twenty seconds
# of interval from each other).
echo 20 > /proc/sys/net/ipv4/tcp_keepalive_time
echo 6 > /proc/sys/net/ipv4/tcp_keepalive_probes
File Description 4.9: /bin/init_proc_fs