Specifications

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Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, Release 5.0(3)U2(2)
OL-25782-02
Chapter 6 Configuring Advanced BGP
Configuring Advanced BGP
Configuring Aggregate Addresses
You can configure aggregate address entries in the BGP route table.
To configure an aggregate address, use the following command in router address-family configuration
mode:
Configuring BGP Conditional Advertisement
You can configure BGP conditional advertisement to limit the routes that BGP propagates. You define
the following two route maps:
• Advertise map—Specifies the conditions that the route must match before BGP considers the
conditional advertisement. This route map can contain any appropriate match statements.
• Exist map or nonexist map—Defines the prefix that must exist in the BGP table before BGP
propagates a route that matches the advertise map. The nonexist map defines the prefix that must not
exist in the BGP table before BGP propagates a route that matches the advertise map. BGP processes
only the permit statements in the prefix list match statements in these route maps.
If the route does not pass the condition, BGP withdraws the route if it exists in the BGP table.
BEFORE YOU BEGIN
Ensure that you have enabled the BGP feature (see the “Enabling the BGP Feature” section on
page 5-11).
SUMMARY STEPS
1. configure terminal
2. router bgp as-number
Command Purpose
aggregate-address ip-prefix/length
[as-set] [summary-only] [advertise-map
map-name] [attribute-map map-name]
[suppress-map map-name]
Example:
switch(config-router-af)#
aggregate-address 192.0.2.0/8 as-set
Creates an aggregate address. The path advertised
for this route is an autonomous system set that
consists of all elements contained in all paths that
are being summarized:
• The as-set keyword generates autonomous
system set path information and community
information from contributing paths.
• The summary-only keyword filters all more
specific routes from updates.
• The advertise-map keyword and argument
specify the route map used to select attribute
information from selected routes.
• The attribute-map keyword and argument
specify the route map used to select attribute
information from the aggregate.
• The suppress-map keyword and argument
conditionally filters more specific routes.