Route Maps To Redistribute Routing Information - Cisco Catalyst 9500 series Configuration Manual

Configuring IP Unicast Routing
Step 4
Step 5

Route Maps to Redistribute Routing Information

Information About Route Maps
The switch can run multiple routing protocols simultaneously, and it can redistribute information from one
routing protocol to another. Redistributing information from one routing protocol to another applies to all
supported IP-based routing protocols.
You can also conditionally control the redistribution of routes between routing domains by defining enhanced
packet filters or route maps between the two domains. The match and set route-map configuration commands
define the condition portion of a route map. The match command specifies that a criterion must be matched.
The set command specifies an action to be taken if the routing update meets the conditions defined by the
match command. Although redistribution is a protocol-independent feature, some of the match and set
route-map configuration commands are specific to a particular protocol.
One or more match commands and one or more set commands follow a route-map command. If there are
no match commands, everything matches. If there are no set commands, nothing is done, other than the match.
Therefore, you need at least one match or set command.
A route map with no set route-map configuration commands is sent to the CPU, which causes high CPU
Note
utilization.
You can also identify route-map statements as permit or deny. If the statement is marked as a deny, the
packets meeting the match criteria are sent back through the normal forwarding channels (destination-based
routing). If the statement is marked as permit, set clauses are applied to packets meeting the match criteria.
Packets that do not meet the match criteria are forwarded through the normal routing channel.
How to Configure a Route Map
Although each of Steps 3 through 14 in the following section is optional, you must enter at least one match
route-map configuration command and one set route-map configuration command.
Command or Action
show ip route
Example:
Device# show ip route
copy running-config startup-config
Example:
Device# copy running-config
startup-config
Routing Configuration Guide, Cisco IOS XE Everest 16.6.x (Catalyst 9500 Switches)
Route Maps to Redistribute Routing Information
Purpose
Displays the selected default route in the
gateway of last resort display.
(Optional) Saves your entries in the
configuration file.
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