Asante Technologies 35516 - Manual (Page 58)

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To define conditions for redistributing routes from a source route entry into the RIP tables, perform at least one of the
following tasks in route-map configuration mode:
Command Purpose
match interface interface-name Match the specified interface.
match ip address {access-list-name |
prefix-list prefix-list-name} Match a standard access list or prefix list.
match ip next-hop access-list-name Match a next-hop router address passed by one of the
access lists specified.
match metric metric-value Match the specified metric.
set ip next-hop ip-address Specify the address of the next hop.
set metric metric-value Set the metric value to give the redistributed routes.
5.4.5 Set Metrics for Redistributed Routes
The metrics of one routing protocol do not necessarily translate into the metrics of another. For example, the RIP
metric is a hop count and the OSPF metric is a combination of five quantities.
In such situations, an artificial metric is assigned to the redistributed route. Because of this unavoidable tampering
with dynamic information, carelessly exchanging routing information between different routing protocols can create
routing loops, which can seriously degrade network operation.
To use the current routing protocol’s metric value for all redistributed routes, enter the following command in router
configuration mode.
Command Purpose
default-metric metric-value Cause the current routing protocol to use the same metric
value for all redistributed routes.
Note: The metric value range is very large for compatibility with other protocols (0-2494967295).
For RIP, valid metric value is from 1 to 16.
5.4.6 Set Administrative Distance
The administrative distance is a value that rates the trustworthiness of a routing information source, such as an
individual router or a group of routers. In a large network, some routing protocols and some routers can be more
reliable than others as sources of routing information. Also, when multiple routing processes are running in the same
router for IP, it is possible for the same route to be advertised by more than one routing process. By specifying
administrative distance values, you enable the router to intelligently discriminate between sources of routing
information.
The router will always pick the route whose routing protocol has the lowest administrative distance. There are no
general guidelines for assigning administrative distances, because each network has its own requirements. You must
determine a reasonable matrix of administrative distances for the network as a whole.