
ifconfig [<subcommand>]

     If a valid subcommand is given, it will be executed (see below).
When no subcommand is given, display a list of interfaces, with a
short status for each.  See the 'ifconfig <iface>' command for a
description of the display.

     ALL ax25 and MOST tcp parameters are now configurable per
interface.  The 'ax25 <cmd>' commands set the system default values
and the 'ifconfig <iface> ax25 <command>' commands set or show the
interface specific value(s).  The 'tcp <cmd>' commands work in the
same manner.

     As a result of this change, 'ifconfig' NO LONGER takes multiple
commands on one line.  'ifconfig ln0 netmask ffffff00 broadcast
255.255.255.255' is invalid.  The command line must be separated into
two commands as: 'ifconfig ln0 netmask ffffff00' and 'ifconfig ln0
broadcast 255.255.255.255'

     

    ifconfig <iface> [<subcommands>]

     When only iface is given, the interface status is displayed.
     
     Interface status shows:
     
        IP addr - the ip address assigned to this interface
        MTU     - the maximum transmission unit for this interface.
        Link encap - the type of link protocol to send packets  with
                  over this interface (AX.25, NETROM etc.)
        Paclen  - if the interface is an AX.25 interface, this is the
                  Paclen used for connections on this interface
        flags   - interface flags, the sum of all the options set with
                  the various commands. See below.

        netmask - the ip network mask. See elsewhere for a discussion.
                  broadcast - the ip broadcast address on this interface.
                  Used when doing arp, etc.
        sent ip - the number of ip packets sent on the interface
        sent tot- the total number of packets sent (i.e. ip, ax.25,
                  etc.)
        sent idle - the elapsed time this interface hasn't transmitted
                  any data.
        recv ip - the number of ip packets received on the interface
        recv tot- the total number of packets received  (i.e. ip,
                  ax.25, etc.)
        recv idle- the elapsed time this interface hasn't received any
                  data.
        descr   - a description of the interface

     Interface flag values are the sums of the following options, and
     can be set or unset (i.e. toggled) with the following commands
     (See their individual descriptions for more)

command           value                  description of flag
mode iface        DATAGRAM_MODE     0    /* Send datagrams in raw
                                            link frames */
                  CONNECT_MODE      1    /* Send datagrams in
                                            connected mode */
netrom interface  IS_NR_IFACE       2    /* Activated for netrom use */
                  NR_VERBOSE        4    /* broadcast routes verbose */
convers interface IS_CONV_IFACE     8    /* Activated for conference
                                            call access */
ax25 bport        AX25_BEACON       16   /* Broadcast AX.25 beacons */
mbox hide         HIDE_PORT         64   /* Don't show port in mbox
                                            'P' command */
ax25 digi         AX25_DIGI         128  /* Allow digipeating */
arp eaves         ARP_EAVESDROP     256  /* Listen to ARP replies */
arp poll          ARP_KEEPALIVE     512  /* Keep arp entries alive
                                            after time-out */
ax25 hport        LOG_AXHEARD       1024 /* Do ax.25 heard logging on
                                            this interface */
ip hport          LOG_IPHEARD       2048 /* Do IP heard logging on this
                                            interface */
mbox noax25       NO_AX25           4096 /* No ax.25 mbox connections on
                                            this interface */
mbox bbsonly      BBS_ONLY          8192 /* BBSes only on this iface */
mbox usersonly    USERS_ONLY       16384 /* Users only on this iface */
mbox sysoponly    SYSOP_ONLY       32768 /* Sysops only on this iface */


    ifconfig <iface> ax25 [<subcommand> [arguments]]

     Sets the value for 'subcommand' per description in the ax25
     commands.  'ifconfig <iface> ax25 ?' by itself displays the
     following list of accepted subcommands:
     
          bbscall
          bctext
          blimit
          cdigi
          irtt
          maxframe
          maxwait
          paclen
          pthresh
          retries
          timertype
          t2
          t3
          t4
          version
          window

    ifconfig <iface> broadcast <addr>

     Set the ip broadcast address of interface <iface> to <addr>.
     

    ifconfig <iface> ax25 cdigi <call>

     Set the 'crossband digipeater only' callsign.  If this call is
     set, digipeating works independently from the 'ax25 digipeat'
     setting.  Connections cannot be made to the cdigi call.  Jnos
     will search for another ax.25 interface with the same Cdigi call
     as that of the interface receiving the digipeated packet, and
     transmit the digipeated packet via that interface.  Example:
         ifconfig 2m ax25 cdigi 2x70
         ifconfig 70cm ax25 cdigi 2x70
     would allow someone to use digipeater call "2x70" to automatically
     transfer between the two interfaces.  Note in this example you
     would probably wish to use beacons to ID the interfaces periodically,
     since the transmissions don't contain your callsign.  This might
     argue for using a valid call-ssid as the cdigi value!
     
    ifconfig <iface> description "descr"

     This command sets the interface description to the string
     specified.  If no descr is supplied (i.e. ""), the current
     description will be cleared.  The description is displayed with
     the mailbox or nodeshell P command (if the interface wasn't
     hidden from that display).  It is also shown in the ifconfig
     command.
     

    ifconfig <iface> encapsulation <mode>

     Sets the encapsulation for interface iface to slip or ax25. This
     should never be needed, since it is automatically executed when
     interfaces are attached.
     

    ifconfig <iface> forward <iface-2>

     When a forward is defined, all output for interface <iface> is
     redirected to <iface-2>.  To remove the forward, set <iface-2> to
     <iface>.
     

    ifconfig <iface> ipaddress <addr>

     Set the IP address to <addr> for this interface. Normally the ip
     address is assigned from the system ip address when the interface
     is first attached. However, it might be necessary to change it
     when a system acts as a ip-gateway.
     

    ifconfig <iface> linkaddress <linkaddr>
     Set the hardware dependent address for this interface.  For AX.25
     this is the callsign.  If you want to allow cross band
     digipeating, give each port a different ax.25 call with this
     command.
     
     
    ifconfig <iface> mtu <num>

     Set the maximum transfer unit to <num> bytes.

     
    ifconfig <iface> netmask <address>

     Set the sub-net mask for this interface.  The <address> takes the
     form of  an IP  address  with 1's in the network and subnet parts
     of the address, and 0's in the host part of the address.  Sample:
     ifconfig  ec0  netmask  0xffffff00 for  a  class  C  network  (24
     bits).  This is related to the 'broadcast' subcommand.  See also
     the 'route' command.
     

    ifconfig <iface> ax25 paclen <num>

     Set the AX.25 paclen for this interface. This is useful if you
     want to use a value different from the default as set with the
     'ax25 paclen' command; e.g., if you have a port with an HF link,
     you might want to set it to 128.  You can also set it to greater
     than 256 if you have a high speed port.  (This command only works
     for interfaces that can carry AX.25 connections, i.e., it is not
     for SLIP interfaces, etc.)
     
     NOTE1:  The AX.25 V2 specification specifies a MAXIMUM of 256 for
     paclen. If you have a paclen > 256, you may run into problems
     when interfacing to other non-NOS systems (in particular G8BPQ-
     based systems.)
     
     NOTE2:  The value of paclen influences NETROM behavior if the
     interface is activated for netrom with the 'netrom interface'
     command!  If the paclen for this interface is smaller than any
     other (netrom active) paclen, the netrom mtu value will be set to
     this paclen - 20 !  This is to assure that you will not get
     fragmentation at the ax.25 level when trying to send large data
     packets over netrom connections.  AX.25 V2.1 fragmentation is
     presently handled only by NOS and derived code as far as is
     known.  Other systems, such as TheNet, BPQ, MSYS,  etc., may not
     include proper handling of V2.1 fragmentation.
     
     What the preceding means is, if you have a VHF port with paclen
     256, and an Hf port with paclen 128, and BOTH are active with
     netrom, the netrom mtu will be 108 !


    ifconfig <iface> rxecho <iface-2>

     When a rxecho interface is defined, all input from interface
     <iface> is also copied (echoed) to <iface-2>.  To remove rxecho,
     set <iface-2> to "off".  This feature requires that RXECHO be
     defined at compile time.
     

    ifconfig <iface> tcp [<command>]

     Sets or displays the 'tcp' command parameters for <iface>.
     'ifconfig <iface> tcp ?' by itself displays the following list:
     
          blimit
          irtt
          maxwait
          mss
          retries
          syndata
          timertype
          window
          
     OUTGOING tcp connections get the values for the interface on
     which the initial sync packet ('connect request') is routed out.
     INCOMING tcp connections get the values for the interface the
     initial request arrives on.
     
     System default TCP parameters must be set PRIOR TO attaching
     interfaces.  After attaching interfaces, use the 'ifconfig
     <iface> tcp' commands to set the interface.
     

