System Administration Commands                       mipagent(1M)

NAME
     mipagent - Mobile IP agent

SYNOPSIS
     /usr/lib/inet/mipagent

DESCRIPTION
     The mipagent utility implements the Mobile IP home agent and
     foreign agent functionality described in RFC 2002, IP Mobil-
     ity Support. The term "mobility agent" is used to  refer  to
     the home agent and foreign agent functionality collectively.
     mipagent responds to Mobile IP registration and  deregistra-
     tion  requests  and  router  discovery solicitation messages
     from a mobile node. Besides responding to external messages,
     the mipagent utility also tasks on a periodic basis, such as
     aging the mobility bindings and visitor entries and  sending
     agent  advertisements.  The  mobility  agent can also handle
     direct delivery style reverse tunneling as specified in  RFC
     2344,  Reverse  Tunneling  for  Mobile  IP.  Limited private
     address support for mobile nodes is also available. In addi-
     tion,  separate  IPsec  policies  for registration requests,
     replies, and tunnel traffic can be configured to protect the
     datagrams associated with these between two mobility agents.

     Run the mipagent daemon as root using the  start-up  script,
     which has the following syntax:


     example# /etc/init.d/mipagent [start|stop]


     /etc/inet/mipagent.conf must be present before you  start-up
     the  mipagent  daemon.  See  mipagent.conf(4).  At start up,
     mipagent   reads   the   configuration   information    from
     /etc/inet/mipagent.conf.  The mipagent daemon records a con-
     tinuous log of its activities  by  means  of  syslog().  See
     syslog(3C).  You  can  use  the  LogVerbosity  parameter  in
     /etc/inet/mipagent.conf to control the  verbosity  level  of
     the log.

     The mipagent daemon can be terminated either by the script:


     example# /etc/init.d/mipagent stop


     or by the kill command.

     Periodically while running, or if  terminated  or  shutdown,
     the  mipagent  daemon  stores  the  following internal state
     information in /var/inet/mipagent_state:

       o  a list of the mobile nodes supported as home agents;

       o  their current care-of addresses; and

       o  the remaining registration lifetimes.

     If the mipagent utility is terminated  for  maintenance  and
     restarted, mipagent_state is used to recreate as much of the
     mobility agent's internal state as possible. This  minimizes
     service  disruption  for  mobile  nodes that may be visiting
     other  networks.   If  mipagent_state  exists,  it  is  read
     immediately  after mipagent.conf when mipagent is restarted.
     The format of mipagent_state is  undocumented  since  it  is
     likely to change and programs other than mipagent should not
     use  it  for  any  purpose.  A  separate   utility   program
     mipagentstat is provided for monitoring mipagent.

EXIT STATUS
     The following exit values are returned:

     0        The daemon started successfully.



     -1       The daemon failed to start.



FILES
     /etc/inet/mipagent.conf                 Configuration   file
                                             for Mobile IP mobil-
                                             ity agent.



     /var/inet/mipagent_state                File  where  private
                                             state    information
                                             from   mipagent   is
                                             stored.



     /etc/init.d/mipagent [start|stop]       mipagent    start-up
                                             script.



ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWmipu                    |
    |_____________________________|_____________________________|


SEE ALSO
     mipagentstat(1M),      mipagentconfig(1M),       syslog(3C),
     mipagent.conf(4), attributes(5)

     Montenegro,  G.,  editor.RFC  2344,  Reverse  Tunneling  for
     Mobile IP. Network Working Group. May 1998.

     Perkins, C. RFC 2002, IP Mobility Support.  Network  Working
     Group. October 1996.

DIAGNOSTICS
     The mipagent utility exits with an error if  the  configura-
     tion  file, mipagent.conf, cannot be read successfully. Upon
     receiving a SIGTERM or SIGINT signal,  mipagent  cleans  its
     internal state, including any changes to the routing and ARP
     tables, and exits.

NOTES
     The foreign agent adds host- specific local  routes  to  its
     routing  table for visiting mobile nodes after they are suc-
     cessfully registered. If  a  visiting  mobile  node  departs
     without   sending  a  de-registration  message  through  the
     foreign agent,  these  routing  entries  persist  until  the
     mobile  node's  previous  registration  expires. Any packets
     that arrive at the foreign agent  for  the  departed  mobile
     node during this time, for example because the foreign agent
     is also a router for the foreign network, will be lost. Sys-
     tem  administrators  can  configure foreign agents to accept
     only short registration lifetimes. This  will  automatically
     restrict  the  maximum  duration for which a departed mobile
     node will be temporarily unreachable.

      Home and foreign agents dynamically add  and  delete  IPsec
     policies  configured  with a mobility agent peer. Those per-
     taining to the tunnel are only  added  when  the  tunnel  is
     plumbed. At this time, IPsec tunnel policies must be identi-
     cal in the forward and  reverse  direction.  IPsec  policies
     pertaining  to  permiting  registration requests on the home
     agent are added to the IPsec policy file at init time as  it
     must be ready to receive these at any time. Otherwise, IPsec
     policies pertaining to registration request and  reply  mes-
     sages  with  a mobility agent peer are added as soon as they
     are needed, and are not removed until all mobile  nodes  are
     no  longer registered with the mobility agent peer, at which
     point the tunnels are torn down.