Installation guide

Operating System Requirements
Chapter 2 Computer System Requirements 27
Tuning TCP Parameters
By default, the TCP/IP implementationin a Solariskernel is not correctly tuned for
Internet or Intranet services. The following
/dev/tcp tuning parameters should be
inspected and, if necessary, changed to fit the network topology of the installation
environment.
The
tcp_time_wait_interval in Solaris 8 specifies the number of milliseconds
that a TCP connection will be held in the kernel’s table after it has been clos ed. If its
value is above 30000 (30 seconds) and the directory is being used in a LAN, MAN
or under a single network adm inistration, it should be reduced by adding a line
similar to the following to the
/etc/init.d/inetinit file:
ndd -set /dev/tcp tcp_close_wait_interval 30000
The tcp_conn_req_max_q0 and tcp_conn_req_max_q parameters control the
maximum backlog of connections that the kernel will accept on behalf of the
Directory Server process. If the directory is expected to be used by a large number
of client hosts simultaneously, these values should be raised to at least 1024 by
adding a line similar to the following to the
/etc/init.d/inetinit file:
ndd -set /dev/tcp tcp_conn_req_max_q0 1024
ndd -set /dev/tcp tcp_conn_req_max_q 1024
The tcp_keepalive_interval specifies the interval in seconds between keepalive
packets sent by Solaris for each open TCP connection. This can be used to remove
connections to clients that have become disconnected from the network.
The
tcp_rexmit_interval_initial value should be inspected when performing
server performance testing on a LAN or high speed MAN or WAN. For operations
on the wide area Internet, its value need not be changed.
The
tcp_smallest_anon_port controls the number of simultaneous connections
thatcanbemadetotheserver.When
rlim_fd_max has been increased to above
4096, this value should be decreased, by adding a line similar to the following to
the
/etc/init.d/inetinit file:
ndd -set /dev/tcp tcp_smallest_anon_port 8192
The tcp_slow_start_initial parameter should be inspected if clients will
predominately be using the Windows TCP/IP stack.
CAUTION This parameter should no t be raised above 4096 without first
consulting you r Sun Solaris support represent ative as it may affect
the stability of the system.