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Route Filter Match Conditions

When specifying a destination prefix, you can specify an exact match with a specific route, or a less precise match by using match types. You can configure either a common reject action that applies to the entire list, or an action associated with each prefix.

You can specify known invalid (“bad”) routes to ignore by specifying matches on destination prefixes. Additionally, you can specify that “good” routes be processed in a particular way. For instance, you can group traffic from specific source or destination addresses into forwarding classes to be processed using the class of service (CoS) feature.

Table 1 lists route list match types.

Table 1: Route List Match Types

Match Type

Match Conditions

address-mask netmask-value

All of the following are true:

  • The bit-wise logical AND of the netmask-value pattern and the incoming IPv4 or IPv6 route address and the bit-wise logical AND of the netmask-value pattern and the destination-prefix address are the same. The bits set in the netmask-value pattern do not need to be contiguous.

  • The prefix-length component of the incoming IPv4 or IPv6 route address and the prefix-length component of the destination-prefix address are the same.

Note:

The address-mask routing policy match type is valid only for matching an incoming IPv4 (family inet) or IPv6 (family inet6) route address to a list of destination match prefixes specified in a route-filter statement.

The address-mask routing policy match type enables you to match an incoming IPv4 or IPv6 route address on a configured netmask address in addition to the length of a configured destination match prefix. The length of the route address must match exactly with the length of the configured destination match prefix, as the address-mask match type does not support prefix length variations for a range of prefix lengths.

When the longest-match lookup is performed on a route filter, the lookup evaluates an address-mask match type differently from other routing policy match types. The lookup does not consider the length of the destination match prefix. Instead, the lookup considers the number of contiguous high-order bits set in the netmask value.

exact

The route shares the same most-significant bits (described by prefix-length), and prefix-length is equal to the route's prefix length.

longer

The route shares the same most-significant bits (described by prefix-length), and prefix-length is greater than the route's prefix length.

orlonger

The route shares the same most-significant bits (described by prefix-length), and prefix-length is equal to or greater than the route's prefix length.

prefix-length-range prefix-length2-prefix-length3

The route shares the same most-significant bits (described by prefix-length), and the route's prefix length falls between prefix-length2 and prefix-length3, inclusive.

through destination-prefix

All the following are true:

  • The route shares the same most-significant bits (described by prefix-length) of the first destination prefix.

  • The route shares the same most-significant bits (described by prefix-length) of the second destination prefix for the number of bits in the prefix length.

  • The number of bits in the route's prefix length is less than or equal to the number of bits in the second prefix.

You do not use the through match type in most routing policy configurations.

upto prefix-length2

The route shares the same most-significant bits (described by prefix-length) and the route's prefix length falls between prefix-length and prefix-length2.

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