For HPUX 10.01, 10.10 and 10.20,
the nettune command is used to configure TCP transport parameters.
Example: The following are equivalent to setting KEEP_IDLE to 5 minutes, KEEPINTVL to 60 seconds, and KEEPCNT to 5 (300/60). These values are examples and may not suit specific environment requirements. Progress does not have specific recommendations - the intervals should be set to as long as an inactive connection is considered to be valid. These changes will affect all TCP connections, not just Progress.
$ nettune -s -w tcp_keepstart 300
$ nettune -s -w tcp_keepfreq 60
$ nettune -s -w tcp_keepstop 300
For HPUX 11.0 and above,
nettune is obsolete functionality in HPUX 11 and instead the ndd utility can be used for examining and modifying system-wide transport parameters.
The algorithm of sending TCP keepalive packets changed between HPUX 10 and HPUX 11 (RFC 1122 - Requirements for Internet Hosts - Communication Layers)
The relevant parameters are:
- tcp_keepalive_interval - Interval for sending keepalive probes
- tcp_ip_notify_interval - R1 for established connection
- tcp_ip_abort_interval - R2 for established connection
The parameter tcp_keepalive_interval determines the amount of time that TCP waits for an idle connection with no unacknowledged data before sending keepalive packets.
Default 7200000 ms = 2 hours.
Then send keepalive packets: tcp_ip_notify_interval (R1)
Default 10000 ms = 10 seconds
UNTIL: tcp_ip_abort_interval (R2) is reached (which is the time that a modem would normally need to re-call for example)
Default 600000 ms = 10 minutes
In other words, the keepalive packets are sent R2/R1 times (in HPUX 10 this was the tcp_keepstop parameter) which with the default settings, would mean terminate the idle connection in 2 hours 10 minutes.
The HP-UX 10 nettune utility is obsolete functionality in HPUX 11 and has been included instead in the ndd utility for examining and modifying system-wide transport parameters.
Example:
$ ndd -set [network] [device] [parameter] [value]
$ ndd -set /dev/tcp tcp_keepalive_interval 900000
Use the "ndd -h <timer_name>" for further information.
Progress does not have specific recommendations - the tcp_keepalive_interval should be set to as long as an inactive connection is considered to be valid for. These changes will affect all connections, not just Progress.
