Create a Route Map

A route map consists of a sequence of IP prefix lists, BGP path attributes, and an associated action. The router scans the sequence for an IP address match. If there is a match, the router performs the action and scans no further.

Route maps can be referenced at the BGP neighbor level and for route redistribution.

Prerequisites

• Verify that an IP prefix list or a community list is configured. See Create an IP Prefix List in Manager Mode or Create a Community List.
• For details about using regular expressions to define route-map match criteria for community lists, see Using Regular Expressions to Match Community Lists When Adding Route Maps.

Procedure

1. From your browser, log in with admin privileges to an NSX Manager at https://<nsx-manager-ip-address>.
2. Select Networking > Tier-0 Gateways.
3. To edit a tier-0 gateway, click the menu icon (three dots) and select Edit.
4. Click Routing.
5. Click Set next to Route Maps.
6. Click Add Route Map.
7. Enter a name and click Set to add match criteria.
8. Click Add Match Criteria to add one or more match criteria.
9. For each criterion, select IP Prefix or Community List and click Set to specify one or more match expressions.
   1. If you selected Community List, specify match expressions that define how to match members of community lists. For each community list, the following match options are available:
      • MATCH ANY - perform the set action in the route map if any of the communities in the community list is matched.
      • MATCH ALL - perform the set action in the route map if all the communities in the community list are matched regardless of the order.
      • MATCH EXACT - perform the set action in the route map if all the communities in the community list are matched in the exact same order.
      • MATCH COMMUNITY REGEXP - perform the set action in the route map if all the regular communities associated with the NRLI match the regular expression.
      • MATCH LARGE COMMUNITY REGEXP - perform the set action in the route map if all the large communities associated with the NRLI match the regular expression.

      You should use the match criterion MATCH_COMMUNITY_REGEX to match routes against standard communities, and use the match criterion MATCH_LARGE_COMMUNITY_REGEX to match routes against large communities. If you want to permit routes containing either the standard community or large community value, you must create two match criteria. If the match expressions are given in the same match criterion, only the routes containing both the standard and large communities will be permitted.

      For any match criterion, the match expressions are applied in an AND operation, which means that all match expressions must be satisfied for a match to occur. If there are multiple match criteria, they are applied in an OR operation, which means that a match will occur if any one match criterion is satisfied.

10. Set BGP attributes.

    BGP Attribute	Description
    AS-path Prepend	Prepend a path with one or more AS (autonomous system) numbers to make the path longer and therefore less preferred.
    MED	Multi-Exit Discriminator indicates to an external peer a preferred path to an AS.
    Weight	Set a weight to influence path selection. The range is 0 - 65535.
    Community	Specify a list of communities. For a regular community use the aa:nn format, for example, 300:500. For a large community use the aa:bb:cc format, for example, 11:22:33. Or use the drop-down menu to select one of the following: NO_EXPORT_SUBCONFED - Do not advertise to EBGP peers. NO_ADVERTISE - Do not advertise to any peer. NO_EXPORT - Do not advertise outside BGP confederation
    Local Preference	Use this value to choose the outbound external BGP path. The path with the highest value is preferred.

11. In the Action column, select Permit or Deny.
    You can permit or deny IP addresses matched by the IP prefix lists or community lists from being advertised.
12. Click Save.