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You can use prefix lists as an alternative to access lists with many BGP
route-filtering commands. The advantages of using prefix lists rather than
access lists include the following:
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Significant performance improvement in loading and route lookup of large lists.
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Support for incremental updates. Filtering via extended access lists does not
support incremental updates.
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A more user-friendly command-line interface.
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Greater flexibility.
You must define a prefix list before you can apply it as a route filter. The
Cisco IOS allows a very flexible configuration procedure, where each statement
can be assigned its own sequence numbers.
To define a prefix list, use the
ip prefix-list
command, which has the syntax shown in Figure .
Figure describes the
parameters that are used with this command.
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