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

NAME
       in.rdisc, rdisc - network router discovery daemon

SYNOPSIS
       /usr/sbin/in.rdisc  [-a] [-f] [-s] [send-address] [receive-address]

       /usr/sbin/in.rdisc  -r [-p preference] [-T interval]
       [send-address] [receive-address]

DESCRIPTION
       in.rdisc remains part of the software distribution of the Solaris Oper‐
       ating Environment. It is, however, not used by  default.	 in.routed(1M)
       includes	 the  functionality provided by in.rdisc. See routeadm(1M) for
       details of how to specify the IPV4 routing daemon.

       in.rdisc implements the ICMP router discovery protocol. The first  form
       of the command is used on hosts and the second form is used on routers.

       in.rdisc	 can be invoked in either the first form (host mode) or second
       form (router mode).

       On a host, in.rdisc populates the network routing tables	 with  default
       routes. On a router, advertises the router to all the hosts.

       in.rdisc	 is managed by the service management facility (SMF), by means
       of the service identifier:

	 svc:/network/routing/rdisc:default

   Host (First Form)
       On a host, in.rdisc listens  on	the  ALL_HOSTS	(224.0.0.1)  multicast
       address	for  ROUTER_ADVERTISE messages from routers. The received mes‐
       sages are handled by first ignoring those listed router addresses  with
       which the host does not share a network. Among the remaining addresses,
       the ones with the highest preference are selected  as  default  routers
       and a default route is entered in the kernel routing table for each one
       of them.

       Optionally, in.rdisc can avoid waiting for routers  to  announce	 them‐
       selves  by  sending  out	 a  few	 ROUTER_SOLICITATION  messages	to the
       ALL_ROUTERS (224.0.0.2) multicast address when it is started.

       A timer is associated with each router address.	The  address  will  no
       longer  be  considered for inclusion in the routing tables if the timer
       expires before a new advertise message is received from the router. The
       address	will  also be excluded from consideration if the host receives
       an advertise message with the preference being  maximally  negative  or
       with a lifetime of zero.

   Router (Second Form)
       When  in.rdisc is started on a router, it uses the SIOCGIFCONF ioctl(2)
       to find the interfaces configured into the system and it starts listen‐
       ing  on	the  ALL_ROUTERS  multicast address on all the interfaces that
       support multicast. It sends out advertise  messages  to	the  ALL_HOSTS
       multicast  address  advertising	all  its  IP  addresses. A few initial
       advertise messages are sent out during the first 30 seconds  and	 after
       that  it	 will transmit advertise messages approximately every 600 sec‐
       onds.

       When in.rdisc receives a solicitation message, it  sends	 an  advertise
       message to the host that sent the solicitation message.

       When in.rdisc is terminated by a signal, it sends out an advertise mes‐
       sage with the preference being maximally negative.

OPTIONS
       Supported options and equivalent	 SMF  service  properties  are	listed
       below. SMF service properties are set using a command of the form:

	 # routeadm -m rdisc:default key=value

       -a		Accept	all routers independent of the preference they
			have in their advertise messages.  Normally,  in.rdisc
			only accepts (and enters in the kernel routing tables)
			the router or routers with the highest preference. Use
			of this option is equivalent to setting the accept_all
			property to true.

       -f		Run in.rdisc forever even if  no  routers  are	found.
			Normally, in.rdisc gives up if it has not received any
			advertise message after	 soliciting  three  times,  in
			which  case  it exits with a non-zero exit code. If -f
			is not specified in the first form  then  -s  must  be
			specified. For SMF execution, this option is required.

       -r		Act  as	 a  router,  rather  than  a host. Use of this
			option is  equivalent  to  setting  the	 act_as_router
			property to true.

       -s		Send  three solicitation messages initially to quickly
			discover the routers when the system is	 booted.  When
			-s  is	specified, in.rdisc exits with a non-zero exit
			code if it can not find any routers. This can be over‐
			ridden with the -f option. This option is not compati‐
			ble with SMF execution and is not  supported  for  the
			rdisc service.

       -p preference	Set  the  preference  transmitted  in the solicitation
			messages. The default is zero. Use of this  option  is
			equivalent to setting the preference property.

       -T interval	Set  the  interval  between transmitting the advertise
			messages. The default time is 600 seconds. Use of this
			option	is equivalent to setting the transmit_interval
			property.

       The send-address and receive-address daemon  options   can  be  set  by
       means of the send_address and receive_address properties.

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

       ┌─────────────────────────────┬─────────────────────────────┐
       │      ATTRIBUTE TYPE	     │	    ATTRIBUTE VALUE	   │
       ├─────────────────────────────┼─────────────────────────────┤
       │Availability		     │SUNWroute			   │
       └─────────────────────────────┴─────────────────────────────┘

SEE ALSO
       in.routed(1M),	routeadm(1M),	svcadm(1M),   ioctl(2),	  gateways(4),
       attributes(5), smf(5), icmp(7P), inet(7P)

       Deering, S.E., editor, ICMP Router Discovery Messages, RFC  1256,  Net‐
       work  Information  Center,  SRI	International, Menlo Park, California,
       September 1991.

SunOS 5.10			  9 Nov 2006			  in.rdisc(1M)

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