net(5) — AIX PS/2 1.2.1



NET(5,F)                    AIX TCP/IP User's Guide                    NET(5,F)



-------------------------------------------------------------------------------
net



PURPOSE

Defines network interface characteristics for TCP/IP for use with the netconfig
command.

SYNOPSIS

/etc/net

DESCRIPTION

The /etc/net file contains the keyword associated with each network interface
that TCP/IP can use and a stanza that describes the characteristics for the
network interface.  There is one stanza entry for each network interface
defined for use with TCP/IP.

The format of network interface stanza in /etc/net/ is:

sys_stanza_name:    dstaddr =

                    inetlen =

                    localbroadcast =

                    netaddr =

                    protocol =

                    r_inetlen =

The information contained in an adapter stanza is:

sys_stanza_name:
        Starting in column one, the name of the network interface defined in
        the /etc/system file.  (The /etc/system file is defined using the
        devices command.)

dstaddr The IP network address for the destination host of a point-to-point
        connection, used for serial line interfaces.  The address must be
        specified in dotted decimal notation.  This keyword is required for a
        point-to-point interface.

inetlen The maximum IP packet length for transmission to this network
        interface.  The default is the maximum packet length defined by the
        system.  The specified value cannot exceed the default value.





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NET(5,F)                    AIX TCP/IP User's Guide                    NET(5,F)



localbroadcast
        An optional keyword application to Token-Ring devices only.  Used to
        indicate if machines on the same Token-Ring Network, but different
        rings, can communicate.  The values can be:

          o true - Only machines on the same ring can communicate.

          o false - Machines on same network but different rings can
            communicate.

        If not specified, the default value is true.

netaddr The IP network address to be used for this adapter.  The address must
        be specified in dotted decimal notation.  This is a required keyword
        for all interfaces.

protocol
        A value used to specify whether an 802.3 interface is being described.
        The value 802.3 indicates an 802.3 interface, while the value standard
        indicates Ethernet headers.  If this keyword is present, its default
        value is standard.

r_inetlen
        An optional, maximum IP packet length for remote transmission
        (transmission outside of the local network).  If not specified, default
        is 576 bytes.  When specified, this value cannot exceed the value of
        inetlen.

        Note:  To specify a sub-network mask different than the default,
        (0xffff0000), add netmask subnetmask to the ifconfig line in
        /etc/rc.tcpip or <LOCAL>/rc.tcpip.local.

The following are sample entries in the /etc/net file:

  1. The following is a stanza for a network adapter, net0, using an IP address
    of "192.100.10.1".  In this example, which uses a class C IP address, the
    four high order bits of the local address represent the subnet number,
    while the four low order bits refer to the local host on the subnetwork.
    The maximum size of packets transmitted outside the local network is 586
    bytes.  Any IP datagram can be sent or received through all interfaces for
    this host.  IP headers for this host do not contain the IP security option.
    The new sub-network mask, (0xffffff00), would be set in the /etc/rc.tcpip
    or <LOCAL>/rc.tcpip.local file.  See note above.

      net0

           netaddr = 192.100.10.1
           inetlen = 1492
           r_inetlen = 586

  2. The following is a stanza for an IBM Token-Ring Adapter using an IP
    address of "128.114.100.1"4.  This interface can communicate with all rings



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NET(5,F)                    AIX TCP/IP User's Guide                    NET(5,F)



    on its Token-Ring network.  Because r_inetlen is not specified, the maximum
    size of packets transmitted outside the local network is 576 bytes.

      tk0

           netaddr = 128.114.100.1
           inetlen = 2010
           localbroadcast = false

  3. Use the following /etc/net stanzas to establish a serial line interface on
    two hosts that are connected by a serial cable.  These stanzas establish a
    point-to-point connection.

      a. On the first host, engineer, add the following stanza:

          tty1:

               netaddr = 192.9.201.3
               dstaddr = 192.9.254.7




































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NET(5,F)                    AIX TCP/IP User's Guide                    NET(5,F)




      b. On the second host, market, add the following stanza:

          tty1:

               netaddr = 192.9.254.7
               dstaddr = 192.9.201.3

FILES

/etc/net  Defines network interfaces for TCP/IP.

RELATED INFORMATION

In this book:  "netconfig"








































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