sys_attrs_inet(5)						File Formats Manual						 sys_attrs_inet(5)

NAME

       sys_attrs_inet - inet subsystem attributes

DESCRIPTION

       This  reference	page lists and describes attributes for the Internet (inet) kernel subsystem. Refer to the sys_attrs(5) reference page for
       an introduction to the topic of kernel subsystem attributes.

	      The number of hash buckets in the kernel interface alias table  (in_ifaddr).  The value of the inifaddr_hsize  attribute	is  always
	      rounded down to the nearest power of 2. The maximum value is 512.

	      Default value: 32 (hash buckets)

	      Minimum value: 16

	      Maximum value: 512

	      The default Internet Protocol (IP) time-to-live value.

	      Default value: DEFTTL, or 64 (router hops)

	      Minimum value: 0

	      Maximum value: 255

	      A  value that enables (1) or disables (0) a check to determine whether an IP datagram whose destination address is a directed broad-
	      cast address has been received on the interface corresponding to that broadcast address.

	      Default value: 0 (disabled)

	      A value that enables (1) or disables (0) a system's ability to forward IP packets that are not addressed to the system.  This  func-
	      tionality is usually enabled by using the /usr/sbin/iprsetup command.

	      Default value: 0 (disabled)

	      For systems functioning as routers, both ipforwarding and ipgateway attributes must be 1.

	      Maximum time an IP fragment can spend waiting to be reassembled.

	      Default value: IPFRAGTTL (60, in units of .5 seconds, or 30 seconds)

	      Minimum value: 1

	      Maximum value: INT_MAX, or 2 billion

	      A  value that enables (1) or disables (0) a system's ability to forward IP packets that are not addressed to the system.	This func-
	      tionality is usually enabled by using the /usr/sbin/iprsetup command.

	      Default value: 0 (disabled)

	      For systems functioning as routers, both ipforwarding and ipgateway attributes must be 1.

	      The number of times a system can simultaneously make outgoing connections to other systems.  The number of  outgoing  ports  is  the
	      value  of  the  ipport_userreserved  attribute  minus  the value of the ipport_userreserved_min attribute.  The default value of the
	      attribute is 5000; therefore, the default number of outgoing ports is 3976.

	      Default value: 5000

	      Minimum value: 1

	      Maximum value: 65535

	      The lower limit of range of port numbers available for use by a TCP or UDP application.  The number of outgoing ports is	the  value
	      of  the  ipport_userreserved attribute minus the value of the ipport_userreserved_min attribute.	The default value of the attribute
	      is 5000; therefore, the default number of outgoing ports is 3976.

	      Default value: 1024

	      Minimum value: 1

	      Maximum value: 65535

	      Maximum length of the IP input queue (ipintrq) before input packets are dropped.

	      Default value: 1024 (bytes)

	      Minimum value: 1024

	      Maximum value: 65535

	      Maximum number of IP input queues.

	      Default value: 1 (queues)

	      Minimum value: 1

	      Maximum value: 64

	      A value that enables (1) or disables (0) the sending of ICMP redirect messages.

	      Default value: 1 (enabled)

	      Enables (1) or disables (0) source routing.

	      Default value: 1 (enabled)

	      Time to wait after a decrease in a PMTU value before attempting to  determine if the PMTU value has increased.

	      Default value: PMTU_DECREASE_INTVL, or 1200 (in units of .5  seconds)

	      Minimum value: 1

	      Maximum value: UINT_MAX, or 4 billion

	      A value that enables (1) or disables (0) discovery of the path maximum transfer unit (PMTU).

	      Default value: 1 (enabled)

	      Time to wait after an increase in a PMTU value before attempting to determine if the PMTU has increased.

	      Default value: PMTU_INCREASE_INTVL, or 240 (in units of .5  seconds)

	      Minimum value: 1

	      Maximum value: UINT_MAX, or 4 billion

	      The timer processing interval for routes participating in the PMTU discovery process.

	      Default value: PMTU_RT_CHECK_INTVL, or 20 (in units of .5 seconds)

	      Minimum value: 1

	      Maximum value: UINT_MAX, or 4 billion

	      A value that enables (1) or disables (0), consideration of all IP addresses in the same network as being local.  When this value	is
	      1,  all  IP addresses that are in different subnets but in the same network are considered local.  When this value is 0, only the IP
	      addresses that match a directly connected subnet are considered local.

	      Default value: 1 (enabled)

	      The number of Transmission Control Protocol (TCP) hash tables.

	      Default value: 1 (table)

	      Minimum value: 1

	      Maximum value: 64

	      The number of buckets in the TCP inpcb hash table.

	      Default value: 512 (buckets)

	      Minimum value: 0

	      Maximum value: INT_MAX, or 2 billion

	      Enables (1) or disables (0) optimization of the listen path for server sockets.

	      Default value: 1 (enabled)

	      A value that enables (1) or disables (0) 4.2 BSD-compatible behavior for the initial send sequence of numbers and keepalives.

	      Default value: 1 (enabled)

	      The number of initial segments to send during congestion window negotiation.

	      Default value: 2 (segments)

	      Minimum value: 1

	      Maximum value: UINT_MAX, or 4 billion

	      A value that enables (0) or disables (1) window scaling.

	      Default value: 0 (enabled)

									      Note

	      The values for disabling and enabling are the reverse of what they are for most other attributes.

	      A value that enables (1) or disables (0) TCP keepalive for all sockets. TCP keepalive supports the periodic transmission of messages
	      on  a connected socket in order to keep connections active. If keepalive is enabled, sockets that do not exit cleanly are cleaned up
	      when the keepalive interval expires.  If	keepalive is not enabled, those sockets will continue to exist until you reboot  the  sys-
	      tem.

	      Default value: 0 (disabled)

	      Applications enable keepalive for sockets by setting the setsockopt() function's SO_KEEPALIVE option.  Use the tcp_keepalive_default
	      attribute to override programs that do not set keepalive on their own, particularly if you have no access to the sources	for  those
	      programs.

	      Maximum number of keepalive probes that can be sent before a connection is dropped.

	      Default value: TCPTV_KEEPCNT, or 8 (probes)

	      Minimum value: 1

	      Maximum value: 32767

	      Idle time before the first keepalive probe.

	      Default value: TCPTV_KEEP_IDLE, or 14400 (in units of .5 seconds)

	      Minimum value: 1

	      Maximum value: 32767

	      Initial connect timeout.

	      Default value: TCPTV_KEEP_INIT, or 150 (in units of .5 seconds)

	      Minimum value: 1

	      Maximum value: 32767

	      Time between keepalive probes.

	      Default value: TCPTV_KEEP_INTVL, or 150 (in units of .5 seconds)

	      Minimum value: 1

	      Maximum value: 32767

	      The maximum lifetime of a TCP segment.

	      Default value: 60 (in units of .5 seconds)

	      Minimum value: 1

	      Maximum value: 2 billion

	      Default maximum segment size.

	      Default value: TCP_MSS, or 536 (bytes)

	      Minimum value: 1

	      Maximum value: 2 billion

	      Default receive buffer size for TCP sockets.

	      Default value: TCP_RECVSPACE, or 61440 (bytes)

	      Minimum value: 1

	      Maximum value: 4 billion (cannot be larger than sb_max)

	      Minimum amount of time between TCP retransmissions.

	      Default value: 2 (in units of .5 seconds), or 1 second

	      Minimum value: 1

	      Maximum value: 2 billion

	      The maximum number of TCP retransmitted packets to send before giving up.

	      Default value: 128 (packets)

	      Minimum value: 1

	      Maximum value: INT_MAX, or 2 billion

	      Initial assumed round-trip time, in seconds.

	      Default value: 3 (seconds)

	      Minimum value: 0

	      Maximum value: INT_MAX, or 2 billion

	      Default send buffer size, in bytes, for TCP sockets.

	      Default value: TCP_SENDSPACE, or 61440 (bytes)

	      Minimum value: 1

	      Maximum value: UINT_MAX, or 4 billion (cannot be larger than sb_max)

	      IP time-to-live, in router hops, for TCP packets.

	      Default value: TCP_TTL, or 60 (router hops)

	      Minimum value: 0

	      Maximum value: 255

	      A  value that enables (1) or disables (0) 4.2 BSD-compatible behavior for an urgent pointer.  The urgent pointer is a pointer to the
	      first octet of data past the urgent section.  When disabled, the urgent pointer is a pointer to the last octet of data in the urgent
	      section.

	      Default value: 1 (enabled)

	      A value that enables (0) or disables (1) delayed acknowledgments.

	      Default value: 0 (enabled)

									      Note

	      The values for disabling and enabling are the reverse of what they are for most other attributes.

	      Number of duplicate acknowledgments (ACKs) before retransmission.

	      Default value: TCPREXMTTHRESH, or 3 (duplicate acknowledgements)

	      Minimum value: 1

	      Maximum value: INT_MAX, or 2 billion

	      A value that enables (1) or disables (0) the movement of TCP inpcbs in  the TIME_WAIT state to the end of the inpcb list.

	      Default value: 0 (disabled)

	      Default receive buffer size, in bytes, for UDP sockets.

	      Default value: UDP_RECVSPACE, or 42240 (bytes)

	      Minimum value: 1

	      Maximum value: UINT_MAX, or 4 billion (cannot be larger than sb_max)

	      Default send buffer size, in bytes, for UDP sockets.

	      Default value: UDP_SENDSPACE, or 9216 (bytes)

	      Minimum value: 1

	      Maximum value: UINT_MAX, or 4 billion (cannot be larger than sb_max)

	      IP time-to-live, in router hops, for UDP packets.

	      Default value: UDP_TTL, or 30 (router hops)

	      Minimum value: 0

	      Maximum value: 255

	      A value that enables (1) or disables (0) checksumming in the Internet user datagram  protocol (UDP).

	      Default value: 1 (enabled)

SEE ALSO

       sys_attrs(5)

       Tuning Tru64 UNIX for Internet Servers at the following location: http://www.digital.com/internet/document/ias/tuning.html.

       System Configuration and Tuning

																 sys_attrs_inet(5)