IN.RIPNGD(8) Maintenance Commands and Procedures IN.RIPNGD(8)

NAME

in.ripngd - network routing daemon for IPv6

SYNOPSIS

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

DESCRIPTION

in.ripngd is the IPv6 equivalent of in.routed(8). It is invoked at
boot time to manage the network routing tables. The routing daemon
uses the Routing Information Protocol for IPv6.


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

svc:/network/routing/ripng:default


In normal operation, in.ripngd listens on the udp(4P) 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
packets 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
networks.

OPTIONS

in.ripngd supports the options listed below. Listed with the options
are the equivalent SMF property values. These are set for the
ripng:default service with a command of the form:

# routeadm -m ripng:default key=value


-p n
Send and receive the routing packets from other routers using
the UDP port number n. Use of this option is equivalent to
setting the udp_port property.


-P
Do not use poison reverse. Use of this option is equivalent
to setting the poison_reverse property to false.


-q
Do not supply routing information. Use of this option is
equivalent to setting the quiet_mode property to true.


-s
Force in.ripngd to supply routing information whether it is
acting as an internetwork router or not. Use of this option
is equivalent to setting the supply_routes property to true.


-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. Not supported by the ripng service.


-v
Print all changes made to the routing tables to standard
output with a timestamp. Use of this option is equivalent to
setting the verbose property to true.

Any other argument supplied to this option 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 instead
of being sent to standard output.

The logfile can be specified for the ripng service by means
of the log_file property.

SEE ALSO

ioctl(2), udp(4P), attributes(7), smf(7), in.routed(8), routeadm(8),
svcadm(8)


G. Malkin, R. Minnear, 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(8). 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 means of the route(8) 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.

August 13, 2023 IN.RIPNGD(8)