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irdpd(8) [minix man page]

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

NAME
irdpd - internet router discovery protocol daemon SYNOPSIS
irdpd [-bsd] [-U udp-device] [-I ip-device] [-o priority-offset] DESCRIPTION
Irdpd looks for routers. This should be a simple task, but many routers are hard to find because they do not implement the router discov- ery protocol. This daemon collects information that routers do send out and makes it available. At startup irdpd sends out several router solicitation broadcasts. A good router should respond to this with a router advertisement. If a router advertisement arrives then no more solicitations are sent. The TCP/IP server has filled its routing table with the info from the advertisement, so it now has at least one router. If the advertisement is sent by a genuine router (the sender is in the table) then the irdpd daemon goes dormant for the time the advert is valid. Routers send new adverts periodically, keeping the daemon silent. Otherwise irdpd will listen for RIP (Router Information Protocol) packets. These packets are sent between routers to exchange routing information. Irdpd uses this information to build a routing table. Every now and then a router advertisement is sent to the local host to give it router information build from the RIP packets. Lastly, if a router solicitation arrives and there is no router around that sends advertisements, then irdpd sends an advertisement to the requestor. Note that this is a direct violation of RFC1256, as no host is supposed to sent those adverts. But alas the world is not always perfect, and those adverts make booting hosts find routers quickly with this help from their brothers. (Of course, they will lose the router soon if they don't have an irdpd daemon themselves.) OPTIONS
-b Broadcast advertisements instead of sending them to the local host only. This may be used to keep (non-Minix) hosts alive on a net without adverts. -s Be silent, do not send advertisements to hosts that ask for them. -d Debug mode, tell where info is coming from and where it is sent. Debugging can also be turned on at runtime by sending signal SIGUSR1 or turned off with SIGUSR2. -o priority-offset Offset used to make the gateway's preferences collected from RIP packets look worse than those found in genuine router adverts. By default -1024. SEE ALSO
set_net_default(8), boot(8), inetd(8), nonamed(8), rarpd(8). BUGS
Under standard Minix this daemon can't listen to two both IRDP and RIP at the same time, so it starts out with IRDP. It switches over to RIP if it can't find a router, or if it threatens to lose its router. It does not switch back. Irdpd may help a host that should not be helped, i.e. if it doesn't have an irdpd daemon with RIP collecting trickery. It will make System Administrators pull out their remaining hair trying to find out why a host can access outside networks for a some time after boot, but goes blind afterwards. AUTHOR
Kees J. Bot (kjb@cs.vu.nl) IRDPD(8)

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RTADVD(8)						    BSD System Manager's Manual 						 RTADVD(8)

NAME
rtadvd -- router advertisement daemon SYNOPSIS
rtadvd [-dDfMRs] [-c configfile] interface ... DESCRIPTION
rtadvd sends router advertisement packets to the specified interfaces. The program will daemonize itself on invocation. It will then send router advertisement packets periodically, as well as in response to router solicitation messages sent by end hosts. Router advertisements can be configured on a per-interface basis, as described in rtadvd.conf(5). If there is no configuration file entry for an interface, or if the configuration file does not exist altogether, rtadvd sets all the parame- ters to their default values. In particular, rtadvd reads all the interface routes from the routing table and advertises them as on-link prefixes. rtadvd also watches the routing table. By default, if an interface direct route is added/deleted on an advertising interface and no static prefixes are specified by the configuration file, rtadvd adds/deletes the corresponding prefix to/from its advertising list, respectively. The -s option may be used to disable this behavior. Moreover, if the status of an advertising interface changes, rtadvd will start or stop sending router advertisements according to the latest status. Basically, hosts MUST NOT send Router Advertisement messages at any time (RFC 2461, Section 6.2.3). However, it would sometimes be useful to allow hosts to advertise some parameters such as prefix information and link MTU. Thus, rtadvd can be invoked if router lifetime is explic- itly set zero on every advertising interface. The command line options are: -c Specify an alternate location, configfile, for the configuration file. By default, /etc/rtadvd.conf is used. -d Print debugging information. -D Even more debugging information is printed. -f Foreground mode (useful when debugging). -M Specify an interface to join the all-routers site-local multicast group. By default, rtadvd tries to join the first advertising interface appeared in the command line. This option has meaning only with the -R option, which enables routing renumbering protocol support. -R Accept router renumbering requests. If you enable it, certain IPsec setup is suggested for security reasons. On KAME-based systems, rrenumd(8) generates router renumbering request packets. This option is currently disabled, and is ignored by rtadvd with a warning message. -s Do not add or delete prefixes dynamically. Only statically configured prefixes, if any, will be advertised. Upon receipt of signal SIGUSR1, rtadvd will dump the current internal state into /var/run/rtadvd.dump. Use SIGTERM to kill rtadvd gracefully. In this case, rtadvd will transmit router advertisement with router lifetime 0 to all the interfaces (in accordance with RFC2461 6.2.5). DIAGNOSTICS
The rtadvd utility exits 0 on success, and >0 if an error occurs. FILES
/etc/rtadvd.conf The default configuration file. /var/run/rtadvd.pid contains the pid of the currently running rtadvd. /var/run/rtadvd.dump in which rtadvd dumps its internal state. SEE ALSO
rtadvd.conf(5), rrenumd(8), rtsol(8) HISTORY
The rtadvd command first appeared in WIDE Hydrangea IPv6 protocol stack kit. CAVEAT
There used to be some text that recommended users not to let rtadvd advertise Router Advertisement messages on an upstream link to avoid undesirable icmp6(4) redirect messages. However, based on the later discussion in the IETF ipng working group, all routers should rather advertise the messages regardless of the network topology, in order to ensure reachability. BSD
May 17, 1998 BSD
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