4.3BSD - /usr/man/cat8/XNSrouted.0

XNSROUTED(8C)                                                    XNSROUTED(8C)


NAME
       XNSrouted - NS Routing Information Protocol daemon

SYNOPSIS
       /etc/XNSrouted [ -s ] [ -q ] [ -t ] [ logfile ]

DESCRIPTION
       XNSrouted  is  invoked  at  boot  time  to  manage the Xerox NS routing
       tables.  The NS routing daemon uses the Xerox  NS  Routing  Information
       Protocol in maintaining up to date kernel routing table entries.

       In  normal operation XNSrouted listens for routing information packets.
       If the host is connected to multiple NS networks, it periodically  sup‐
       plies  copies of its routing tables to any directly connected hosts and
       networks.

       When XNSrouted is started, it uses the SIOCGIFCONF ioctl to find  those
       directly  connected  interfaces  configured  into the system and marked
       ‘‘up’’ (the software  loopback  interface  is  ignored).   If  multiple
       interfaces  are  present,  it  is assumed the host will forward packets
       between networks.  XNSrouted then transmits a request  packet  on  each
       interface  (using  a broadcast packet if the interface supports it) and
       enters a loop, listening for request and response  packets  from  other
       hosts.

       When  a  request packet is received, XNSrouted formulates a reply based
       on the information maintained in its  internal  tables.   The  response
       packet  generated  contains  a list of known routes, each marked with a
       ‘‘hop count’’ metric (a count of 16, or greater, is considered  ‘‘infi‐
       nite’’).   The  metric  associated  with each route returned provides a
       metric relative to the sender.

       Response packets received by XNSrouted are used to update  the  routing
       tables if one of the following conditions is satisfied:

       (1)    No  routing  table  entry  exists for the destination network or
              host, and the metric indicates the destination is  ‘‘reachable’’
              (i.e. the hop count is not infinite).

       (2)    The  source  host of the packet is the same as the router in the
              existing routing table entry.  That is, updated  information  is
              being  received  from the very internetwork router through which
              packets for the destination are being routed.

       (3)    The existing entry in the routing table has not been updated for
              some  time  (defined to be 90 seconds) and the route is at least
              as cost effective as the current route.

       (4)    The new route describes a shorter route to the destination  than
              the  one  currently  stored in the routing tables; the metric of
              the new route is compared against the one stored in the table to
              decide this.

       When an update is applied, XNSrouted records the change in its internal
       tables and generates a response packet to all directly connected  hosts
       and  networks.   Routed  waits  a short period of time (no more than 30
       seconds) before modifying the kernel’s routing tables to allow possible
       unstable situations to settle.

       In addition to processing incoming packets, XNSrouted also periodically
       checks the routing table entries.  If an entry has not been updated for
       3  minutes,  the  entry’s  metric  is  set  to  infinity and marked for
       deletion.  Deletions are delayed an additional 60 seconds to insure the
       invalidation is propagated to other routers.

       Hosts  acting as internetwork routers gratuitously supply their routing
       tables every 30 seconds to all directly connected hosts and networks.

       Supplying the -s option forces XNSrouted to supply routing  information
       whether  it  is acting as an internetwork router or not.  The -q option
       is the opposite of the -s option.  If the -t option is  specified,  all
       packets  sent or received are printed on the standard output.  In addi‐
       tion, XNSrouted will not divorce itself from the  controlling  terminal
       so  that interrupts from the keyboard will kill the process.  Any other
       argument  supplied  is  interpreted  as  the  name  of  file  in  which
       XNSrouted’s  actions  should  be logged.  This log contains information
       about any changes to the routing tables and a history  of  recent  mes‐
       sages sent and received which are related to the changed route.

SEE ALSO
       ‘‘Internet Transport Protocols’’, XSIS 028112, Xerox System Integration
       Standard.
       idp(4P)


4.3 Berkeley Distribution        June 4, 1986                    XNSROUTED(8C)