Routing Protocols in the Solaris OS

Solaris system software supports two routing protocols: Routing Information Protocol (RIP) and ICMP Router Discovery (RDISC). RIP and RDISC are both standard TCP/IP protocols.

Routing Information Protocol (RIP)

RIP is implemented by in.routed, the routing daemon, which automatically starts when the system boots. When run on a router with the s option specified, in.routed fills the kernel routing table with a route to every reachable network and advertises “reachability” through all network interfaces.

When run on a host with the q option specified, in.routed extracts routing information but does not advertise reachability. On hosts, routing information can be extracted in two ways:

• Do not specify the S flag (capital “S”: “Space-saving mode”). in.routed builds a full routing table exactly as it does on a router.

• Specify the S flag. in.routed creates a minimal kernel table, containing a single default route for each available router.

ICMP Router Discovery (RDISC) Protocol

Hosts use RDISC to obtain routing information from routers. Thus, when hosts are running RDISC, routers must also run another protocol, such as RIP, in order to exchange router information.

RDISC is implemented by in.routed, which should run on both routers and hosts. On hosts, in.routed uses RDISC to discover default routes from routers that advertise themselves through RDISC. On routers, in.routed uses RDISC to advertise default routes to hosts on directly-connected networks. See the in.routed(1M) man page and the gateways(4) man page.