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SPPPCONTROL(8)          FreeBSD System Manager's Manual         SPPPCONTROL(8)

     spppcontrol -- display or set parameters for an sppp interface

     spppcontrol [-v] ifname [parameter[=value]] [...]

     The sppp(4) driver might require a number of additional arguments or
     optional parameters besides the settings that can be adjusted with
     ifconfig(8).  These are things like authentication protocol parameters,
     but also other tunable configuration variables.  The spppcontrol utility
     can be used to display the current settings, or adjust these parameters
     as required.

     For whatever intent spppcontrol is being called, at least the parameter
     ifname needs to be specified, naming the interface for which the settings
     are to be performed or displayed.  Use ifconfig(8), or netstat(1) to see
     which interfaces are available.

     If no other parameter is given, spppcontrol will just list the current
     settings for ifname and exit.  The reported settings include the current
     PPP phase the interface is in, which can be one of the names dead,
     establish, authenticate, network, or terminate.  If an authentication
     protocol is configured for the interface, the name of the protocol to be
     used, as well as the system name to be used or expected will be dis-
     played, plus any possible options to the authentication protocol if
     applicable.  Note that the authentication secrets (sometimes also called
     keys) are not being returned by the underlying system call, and are thus
     not displayed.

     If any additional parameter is supplied, superuser privileges are
     required, and the command works in the ``set'' mode.  This is normally
     done quietly, unless the option -v is also enabled, which will cause a
     final printout of the settings as described above once all other actions
     have been taken.  Use of this mode will be rejected if the interface is
     currently in any other phase than dead.  Note that you can force an
     interface into dead phase by calling ifconfig(8) with the parameter down.

     The currently supported parameters include:

                   Set both, his and my authentication protocol to protoname.
                   The protocol name can be one of ``chap'', ``pap'', or
                   ``none''.  In the latter case, the use of an authentication
                   protocol will be turned off for the named interface.  This
                   has the side-effect of clearing the other authentication-
                   related parameters for this interface as well (i.e., system
                   name and authentication secret will be forgotten).

                   Same as above, but only for my end of the link.  I.e., this
                   is the protocol when remote is authenticator, and I am the
                   peer required to authenticate.

                   Same as above, but only for his end of the link.

                   Set my system name for the authentication protocol.

                   Set his system name for the authentication protocol.  For
                   CHAP, this will only be used as a hint, causing a warning
                   message if remote did supply a different name.  For PAP, it
                   is the name remote must use to authenticate himself (in
                   connection with his secret).

                   Set my secret (key, password) for use in the authentication
                   phase.  For CHAP, this will be used to compute the response
                   hash value, based on remote's challenge.  For PAP, it will
                   be transmitted as plain text together with the system name.
                   Do not forget to quote the secrets from the shell if they
                   contain shell metacharacters (or white space).

                   Same as above.

                   Same as above, to be used if we are an authenticator and
                   the remote peer needs to authenticate.

                   Same as above.

           callin  Require remote to authenticate himself only when he is
                   calling in, but not when we are caller.  This is required
                   for some peers that do not implement the authentication
                   protocols symmetrically (like Ascend routers, for example).

           always  The opposite of callin.  Require remote to always authenti-
                   cate, regardless of which side is placing the call.  This
                   is the default, and will not be explicitly displayed in the
                   ``list'' mode.

                   Only meaningful with CHAP.  Do not re-challenge peer once
                   the initial CHAP handshake was successful.  Used to work
                   around broken peer implementations that cannot grok being
                   re-challenged once the connection is up.

                   With CHAP, send re-challenges at random intervals while the
                   connection is in network phase.  (The intervals are cur-
                   rently in the range of 300 through approximately 800 sec-
                   onds.)  This is the default, and will not be explicitly
                   displayed in the ``list'' mode.

                   Allows to change the value of the LCP restart timer.  Val-
                   ues are specified in milliseconds.  The value must be
                   between 10 and 20000 ms, defaulting to 3000 ms.

                   Enable negotiation of Van Jacobsen header compression.
                   (Enabled by default.)

                   Disable negotiation of Van Jacobsen header compression.

                   Enable negotiation of the IPv6 network control protocol.
                   (Enabled by default if the kernel has IPv6 enabled.)

                   Disable negotiation of the IPv6 network control protocol.
                   Since every IPv4 interface in an IPv6-enabled kernel auto-
                   matically gets an IPv6 address assigned, this option pro-
                   vides for a way to administratively prevent the link from
                   attempting to negotiate IPv6.  Note that initialization of
                   an IPv6 interface causes a multicast packet to be sent,
                   which can cause unwanted traffic costs (for dial-on-demand

     # spppcontrol bppp0
     bppp0:  phase=dead
             myauthproto=chap myauthname="uriah"
             hisauthproto=chap hisauthname="ifb-gw" norechallenge

     Display the settings for bppp0.  The interface is currently in dead
     phase, i.e., the LCP layer is down, and no traffic is possible.  Both
     ends of the connection use the CHAP protocol, my end tells remote the
     system name ``uriah'', and remote is expected to authenticate by the name
     ``ifb-gw''.  Once the initial CHAP handshake was successful, no further
     CHAP challenges will be transmitted.  There are supposedly some known
     CHAP secrets for both ends of the link which are not being shown.

     # spppcontrol bppp0 \
             authproto=chap \
             myauthname=uriah myauthsecret='some secret' \
             hisauthname=ifb-gw hisauthsecret='another' \

     A possible call to spppcontrol that could have been used to bring the
     interface into the state shown by the previous example.

     netstat(1), sppp(4), ifconfig(8)

     B. Lloyd and W. Simpson, PPP Authentication Protocols, RFC 1334.

     W. Simpson, Editor, The Point-to-Point Protocol (PPP), RFC 1661.

     W. Simpson, PPP Challenge Handshake Authentication Protocol (CHAP), RFC

     The spppcontrol utility appeared in FreeBSD 3.0.

     The program was written by Jorg Wunsch, Dresden.

FreeBSD 6.2                    December 30, 2001                   FreeBSD 6.2


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