Allied Telesis AT-S63 - Manual (Page 332)

Chapter 29: Internet Protocol Version 4 Packet Routing
332 Section VII: Routing
Routing Information Protocol (RIP)
A switch can automatically learn routes to remote destinations by sharing
the contents of its routing table with its neighboring routers in the network
with the Routing Information Protocol (RIP) versions 1 and 2.
RIP is a fairly simple distance vector routing protocol that defines networks
based in how many hops they are from the switch, just as with static
routes. A network that is more than fifteen hops away (one hop is one link)
is considered as unreachable and is not included in the routing table.
RIP version 2 permits the addition of subnet masks and next hop
information in RIP updates. This allows the use of different sized subnet
masks on different subnets within the same network.
RIP broadcasts are automatically activated when the protocol is added to
a routing interface on the switch. An interface sends RIP packets to the
RIP multicast address 224.0.0.9 when sending version 2 packets or uses
the broadcast address when sending out version 1 packets.
A route is propagated by RIP if its status at the physical level is active. An
active route has at least active one port in the VLAN. RIP does not
propagate an inactive route where there are no active ports in the VLAN.
RIP can be added to a maximum of 100 interfaces on a switch and the
route table can store up to 1024 dynamic routes.
Since the interfaces on a switch can route packets among the local
subnets without the presence of RIP or static routes, the routing protocol is
only necessary if the switch is to learn remote destinations by sharing the
switch’s routing table with the neighboring routers, and you choose not to
specify the routes manually with static routes.
You add RIP to the routing interfaces where there are neighboring routers
to remote destinations. You do not need to add RIP to interfaces where
there are no neighboring routers.
A route learned by RIP is immediately added to the routing table, where it
becomes available to all the interfaces on the switch.
When you add RIP to an interface, you can specify the type of RIP packets
the routing protocol is to send and receive. The AT-9400 Switch can send
either version 1 or 2 packets and accept either or both versions.
Version 2 supports the addition of a password of up to sixteen
alphanumeric characters to protect routers and their tables from
incorporating bogus routing updates. The switch adds the password into
the routing table when it broadcasts the contents of the table to its
neighboring routing devices, which check the password prior to updating
their tables.