【单选题】

One of the most widely used routing protocols in IP networks is the Routing Information Protocol (RIP). RIP is the canonical example of a routing protocol built on the ______ algorithm. Routing protocols in intemetworks differ slightly from the idealized graph model. In an internetwork, the goal of the routers to forward packets to various ______.

Routers running RIP send their advertisement about cost every ______ seconds.A、router also sends an update message whenever an update from another router causes it to change its routing table.
It is possible to use a range of different metrics or costs for the links in a routing protocol. RIP takes the simplest approach, with all link costs being equal ______. Thus it always tries to fend the minimum hop route. Valid distances are 1 through ______. This also limits RIP to running on fairly small networks.
A、computers B、Routers
C、switches
D、Networks