Administrator Guide

Layer 3 Routing Commands 1419
User Guidelines
The ipv6 prefix-list command is used to create IPv6 prefix lists. These are
similar to ip prefix lists except that the lists are IPv6 specific. An IPv6 prefix
list can contain only IPv6 addresses.
Prefix lists allow matching of route prefixes against those specified in the
prefix list. Each prefix list includes of a sequence of prefix list entries ordered
by sequence numbers. A router examines each prefix list entry in sequential
order to determine if the route’s prefix matches that of the entry. For IPv6
routes, only IPv6 prefix lists are matched. An empty or non-existent prefix list
permits all prefixes. An implicit deny is assumed if a given prefix does not
match any entries of a prefix list. Once a match occurs the router does not
perform matching on the rest of the list.
An IPv6 prefix list may be used within a route map to match a route’s prefix
using the match ipv6 address command. A route map may contain both IPv4
and IPv4 prefix lists. If the route being matched is an IPv6 route, only the
IPv6 prefix lists are matched.
When neither the ge nor the le option is configured, the destination prefix
must match the ipv6-prefix/prefix-length exactly. If the ge option is
configured without the le option, any prefix with a ipv6-prefix greater than or
equal to the ge value is considered a match. Similarly, if the le option is
configured without the ge option, a prefix with a network mask less than or
equal to the le value is considered a match. No description is configured by
default for an IPv6 prefix list.
The command no ipv6 prefix-list list-name deletes the entire prefix list. To
remove an individual statement from a prefix list, specify the statement
exactly, with all its options.
Up to 128 prefix lists may be configured. The maximum number of
statements allowed in prefix list is 64. These numbers indicate only IPv6
prefix lists. IPv4 prefix lists may be configured in appropriate numbers
independently.
Command History
Introduced in version 6.2.0.1 firmware.