routed(8)						      System Manager's Manual							 routed(8)

NAME

       routed - Manages network routing tables

SYNOPSIS

       /usr/sbin/routed [-q | -s] [-dgt] [logfile]

       The routed daemon manages the network routing tables.

FLAGS

       Enables	additional debugging information, such as bad packets received, to be logged.  The routed daemon remains under control of the host
       that started it; therefore, an interrupt from the controlling host stops the routed process.  Causes the routing daemon to run on a gateway
       host.   This  flag  is used on internetwork routers to offer a route to the default destination.  Inhibits the routed daemon from supplying
       Routing Information Protocol (RIP) data.  The -q flag conflicts with the -s flag.  Do not use the -q and -s flags together.  Causes  routed
       to  supply RIP information even if it is not functioning as an Internet router.	The -s flag conflicts with the -q flag.  Do not use the -s
       and -q flags together.  Causes all packets sent or received to be written to standard output.  The routed daemon remains under  control	of
       the host that started it; therefore, an interrupt from the controlling host stops the routed process.

DESCRIPTION

       Use the routed daemon to manage the RIP only.  Use gated to manage RIP plus other protocols.

       When  routed starts, it finds any interfaces to directly connected hosts and networks that are configured into the system and marked as up.
       If multiple interfaces are present, routed assumes that the local host forwards packets between networks.  The routed daemon  transmits	an
       RIP  request  packet  on  each  interface (using a broadcast packet if the interface supports it) and then enters a loop, listening for RIP
       routing requests and response packets from other hosts.	In addition, if routed is to supply RIP information to other  hosts,  it  periodi-
       cally sends RIP update packets (containing copies of its routing tables) to any directly connected hosts and networks.

       When  routed  receives  a  RIP  request packet and can supply RIP routing information, (the -s flag is set), it generates a reply (response
       packet) based on the information maintained in the kernel routing tables.  The response packet contains a list of known routes, each marked
       with  a hop count metric (the number of host-to-host connections in the route).	The metric for each route is relative to the sending host.
       A metric of 16 or greater is considered to be infinite, or beyond reach.

   Updating Routing Tables
       If RIP processing is enabled, routed uses information contained in the RIP response and update packets from other hosts to update its rout-
       ing tables.  However, routed uses the information in the RIP routing packet to update the tables only if at least one of the following con-
       ditions exists: No routing table entry exists for the destination network or host, and the metric associated with the route is finite (that
       is, the metric is less than 16).  The source host of the packet is the router in the existing routing table entry.  The routing table entry
       is old and the new information is about a route that is at least as efficient as the existing route.  The new route is shorter than the one
       that  is  currently  stored in the routing tables.  (Note that routed determines relative route length by comparing the new metric with the
       one stored in the routing table.)

       When routed updates its internal routing tables, it generates an RIP update packet to all directly connected hosts  and	networks.   Before
       updating the kernel routing tables, routed pauses for a brief period to allow any unstable conditions to stabilize.

       Besides processing incoming RIP packets, routed also checks the internal routing table entries periodically.  The metric for any entry that
       has not been updated for 3 minutes is set to infinity and marked for deletion.  The deletion is delayed for 60 seconds so that  information
       about  the  invalidated	route can be distributed throughout the network.  A host that acts as an RIP router supplies its routing tables to
       all directly connected hosts and networks every 30 seconds.

   Using Gateways
       In addition to managing routes to directly connected hosts and networks, routed maintains information about distant and external  gateways.
       At startup, routed reads the /etc/gateways file to learn about these gateways.

       The /etc/gateways file contains information about routes through distant and external gateways to hosts and networks that can be advertised
       through RIP.  These routes are either static routes to specific destinations, or default routes that apply when a static route to a  desti-
       nation is unspecified.

       Gateways  that  supply  RIP  routing  information  are marked active in the /etc/gateways file.	The routed daemons distributes RIP routing
       information to active gateways; if no RIP routing information is received from the gateway for a period of time, routed deletes the associ-
       ated route from the routing tables.

       Gateways  that  do  not	exchange RIP routing information are marked passive in the /etc/gateways file.	Routed maintains information about
       passive gateways indefinitely, and includes information about them in any RIP routing information transmitted.

       Gateways are identified as external to inform routed that another routing process installs the route.

       Information about external gateways is not maintained in the routing tables.  Note that routes through external gateways must  be  to  net-
       works only.

       If  a  logfile is specified, routed writes information about its actions to the specified log file.  The log contains information about any
       changes to the routing tables and a history of recent route change messages sent and received that are related to changed routes.

   Signals
       The following signals have the specified effect when sent to the routed process	using  the  kill(1)  command:  Displays  internal  routing
       tables.	Broadcasts RIP packets with hop counts set to infinity.  Essentially, these signals disable the local host as a router.  On a sec-
       ond SIGHUP, SIGTERM, or SIGQUIT, routed terminates.

FILES

       Specifies the command path Routes through distant and external gateways Contains the network name database

CAUTIONS

       The gated and routed daemons should not both be run on the same host, as this may produce unpredictable results.  Routes  through  external
       gateways must be to networks only.

RELATED INFORMATION

       Commands: route(8)

       Daemons: gated(8) delim off

																	 routed(8)