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What is metric in route command?
More information. A metric is a value that’s assigned to an IP route for a particular network interface. It identifies the cost that’s associated with using that route. For example, the metric can be valued in terms of link speed, hop count, or time delay.
How do route metrics work?
A routing protocol uses a metric to determine which route to include in the routing table when it has two available routes to the same destination. The router will include the route with the smallest metric because it considers this route to be the shortest—and therefore best.
What are the routing metrics to find best route?
Router metrics can contain any number of values that help the router determine the best route among multiple routes to a destination. A router metric typically based on information like path length, bandwidth, load, hop count, path cost, delay, MTU, reliability and communications cost.
Which metric is used to determine routes using RIP?
hop count
Routing Information Protocol (RIP) uses hop count as the metric to rate the value of different routes. The hop count is the number of devices that can be traversed in a route. A directly connected network has a metric of zero; an unreachable network has a metric of 16.
Why does RIP use UDP?
RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from source to destination. RIP uses the User Datagram Protocol (UDP) as its transport protocol, and is assigned the reserved port number 520.
Why IP route is used?
IP Routing is an umbrella term for the set of protocols that determine the path that data follows in order to travel across multiple networks from its source to its destination. The IP Routing protocols enable routers to build up a forwarding table that correlates final destinations with next hop addresses.
What is the metric for router R2?
In this case, the route going through R2 will have a metric of one, because only one router is in the path to the 10.0.0.0/24 network. The route going through R3 and R4 will have a metric of two. The first route will be placed in the routing table and used for packets sent to the 10.0.0.0/24 subnet.
When to use automatic metric in routing table?
The Automatic Metric feature is enabled by default, and it can also be manually configured to assign a specific metric. The Automatic Metric feature can be useful when the routing table contains multiple routes for the same destination.
When to use hop counts as a routing metric?
In the example above you can see the problem of using hop counts as a routing metric. Imagine if the first path through R2 was the 56 kbps modem link, while the other path is a high speed WAN link. Router R1 would still chose the path going through R2 as the best route, because RIP uses only the hop count as its metric.
Which is the metric for routing R3 or R4?
The route going through R3 and R4 will have a metric of two. The first route will be placed in the routing table and used for packets sent to the 10.0.0.0/24 subnet. In the example above you can see the problem of using hop counts as a routing metric.