Netgear XCM8806 - 8800 SERIES 6-SLOT CHASSIS SWITCH 사용자 설명서
Chapter 22. RIP
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NETGEAR 8800 User Manual
Overview of RIP
RIP is an IGP first used in computer routing in the Advanced Research Projects Agency
Network (ARPAnet) as early as 1969. It is primarily intended for use in homogeneous
networks of moderate size.
Network (ARPAnet) as early as 1969. It is primarily intended for use in homogeneous
networks of moderate size.
To determine the best path to a distant network, a router using RIP always selects the path
that has the least number of hops. Each router that data must traverse is considered to be
one hop.
that has the least number of hops. Each router that data must traverse is considered to be
one hop.
Routing Table
The routing table in a router using RIP contains an entry for every known destination network.
Each routing table entry contains the following information:
Each routing table entry contains the following information:
•
IP address of the destination network
•
Metric (hop count) to the destination network
•
IP address of the next router
•
Timer that tracks the amount of time since the entry was last updated
The router exchanges an update message with each neighbor every 30 seconds (default
value), or when there is a change to the overall routed topology (also called triggered
updates). If a router does not receive an update message from its neighbor within the route
timeout period (180 seconds by default), the router assumes the connection between it and
its neighbor is no longer available.
value), or when there is a change to the overall routed topology (also called triggered
updates). If a router does not receive an update message from its neighbor within the route
timeout period (180 seconds by default), the router assumes the connection between it and
its neighbor is no longer available.
Split Horizon
Split horizon is a scheme for avoiding problems caused by including routes in updates sent to
the router from which the route was learned. Split horizon omits routes learned from a
neighbor in updates sent to that neighbor.
the router from which the route was learned. Split horizon omits routes learned from a
neighbor in updates sent to that neighbor.
Poison Reverse
Like split horizon, poison reverse is a scheme for eliminating the possibility of loops in the
routed topology. In this case, a router advertises a route over the same interface that
supplied the route, but the route uses a hop count of 16, which defines that router as
unreachable.
routed topology. In this case, a router advertises a route over the same interface that
supplied the route, but the route uses a hop count of 16, which defines that router as
unreachable.
Triggered Updates
Triggered updates occur whenever a router changes the metric for a route. The router is
required to send an update message immediately, even if it is not yet time for a regular
update message to be sent. This generally results in faster convergence, but may also result
in more RIP-related traffic.
required to send an update message immediately, even if it is not yet time for a regular
update message to be sent. This generally results in faster convergence, but may also result
in more RIP-related traffic.