Foundation Summary

The Foundation Summary provides a convenient review of many key concepts in this chapter. If you are already comfortable with the topics in this chapter, this summary might help you recall a few details. If you just read this chapter, this review should help solidify some key facts. If you are doing your final prep before the exam, the following lists and tables are a convenient way to review the day before the exam.

The following list summarizes the characteristics of route maps:

• A collection of route map statements with the same name is considered one route map (like an ACL).

• Route maps are processed top down until a match is found (like an ACL).

• Each route map statement has zero or more match conditions. A statement without a match applies to all traffic (like an access-list any). Traffic that is not a match is not changed, but is considered by the next statement.

  - A single match statement can contain multiple conditions. If any one condition is true then a match is made; this is a logical OR.

  - If there are multiple match statements, all must be considered true for the route map statement to be considered matched. This is a logical AND.

• Each route map statement has zero or more set statements. Set statements define an action to be taken.

• Each route map statement has permit or deny permission. Traffic that matches a permit is affected by the route map, traffic that matches a deny, or does not find a match in the list, is not affected by the route map.

• Traffic that is not explicitly permitted is implicitly denied.

• Within a route map, each route map statement has a sequence number and can be edited individually.

The following list characterizes the operation of route map statements:

• The route map statements used for routing can be marked as permit or deny.

• The set commands will be applied only if the statement is marked as permit and the packet meets the match criteria.

• The statements in a route map correspond to the lines of an access list. Specifying the match conditions in a route map is similar to specifying the source and destination addresses and masks in an access list.

• The statements in the route map are compared to the route or packet to see if there is a match. The statements are examined in order starting at the top, like in an access list. The single match statement can contain multiple conditions. At least one condition in the match statement must be true. This is a logical OR.

• A route map statement can contain multiple match statements. All match statements in the route map statement must be considered true for the route map statement to be considered matched. This is a logical AND.

The route-map command syntax is shown here:

Router(config)# route-map map-tag [{permit | deny} sequence-number]