in.ripngd(1M)						  System Administration Commands					     in.ripngd(1M)

NAME

       in.ripngd - network routing daemon for IPv6

SYNOPSIS

       /usr/sbin/in.ripngd [-s] [-q] [-t] [-p n] [-P] [-v ] [logfile]

DESCRIPTION

       in.ripngd  is  the  IPv6  equivalent of in.routed(1M).  It is invoked at boot time to manage the network routing tables. The routing daemon
       uses the Routing Information Protocol for IPv6.

       In normal operation, in.ripngd listens on the udp(7P) socket port 521 for routing information packets.  If  the	host  is  an  internetwork
       router, it periodically supplies copies of its routing tables to any directly connected hosts and networks.

       When  in.ripngd	is  started, it uses the SIOCGLIFCONF ioctl(2) to find those directly connected IPv6 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  pack-
       ets  between  networks.	in.ripngd  then  multicasts  a	request packet on each IPv6 interface and enters a loop, listening for request and
       response packets from other hosts.

       When a request packet is received, in.ripngd formulates a reply based on the information maintained in its internal tables.   The  response
       packet  contains  a list of known routes. With each route is a number specifying the number of bits in the prefix. The prefix is the number
       of bits in the high order part of an address that indicate the subnet or network that the route describes. Each route reported also  has  a
       "hop  count"  metric.  A count of 16 or greater is considered "infinity."  The metric associated with each route returned provides a metric
       relative to the sender.

       The request packets received by in.ripngd are used to update the routing tables if one of the following conditions is satisfied:

	 o  No routing table entry exists for the destination network or host, and the metric indicates the destination is "reachable",  that  is,
	    the hop count is not infinite.

	 o  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.

	 o  The existing entry in the routing table has not been updated for a period of time, defined to be 90 seconds, and the route is at least
	    as cost-effective as the current route.

	 o  The  new route describes a shorter route to the destination than the one currently stored in the routing tables; this is determined by
	    comparing the metric of the new route against the one stored in the table.

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

       In addition to processing incoming packets, in.ripngd 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 throughout the internet.

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

OPTIONS

       in.ripngd supports the following options:

       -q	       Do not supply routing information.

       -s	       Force in.ripngd to supply routing information whether it is acting as an internetwork router or not.

       -p n	       Send and receive the routing packets from other routers using the UDP  port number n.

       -P	       Do not use poison reverse.

       -t	       Print  all  packets  sent  or received to standard output. in.ripngd will not divorce itself from the controlling terminal.
		       Accordingly, interrupts from the keyboard will kill the process.

       -v	       Print all changes made to the routing tables to standard output with a timestamp.

		       Any other argument supplied is interpreted as the name of the file in which the actions of in.ripngd, as specified by  this
		       option or by -t, should be logged versus being sent to standard output.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWroute 		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       in.routed(1M), ioctl(2), attributes(5), udp(7P)

       Malkin, G., Minnear, R., RFC 2080, RIPng for IPv6, January 1997.

NOTES

       The kernel's routing tables may not correspond to those of in.ripngd for short periods of time while processes that utilize existing routes
       exit; the only remedy for this is to place the routing process in the kernel.

       in.ripngd currently does not support all of the functionality of in.routed(1M). Future releases may support more if appropriate.

       in.ripngd initially obtains a routing table by examining the interfaces configured on a machine. It then sends a request  on  all  directly
       connected  networks  for  more  routing information. in.ripngd does not recognize or use any routing information already established on the
       machine prior to startup. With the exception of interface changes, in.ripngd does not see any routing table changes that have been done	by
       other  programs	on  the machine, for example, routes added, deleted or flushed by way of the route(1M) command.  Therefore, these types of
       changes should not be done while  in.ripngd is running. Rather, shut down in.ripngd, make the changes required, and then restart in.ripngd.

SunOS 5.10							    6 Nov 2000							     in.ripngd(1M)