route map you specify with the non-exist-map keyword references multiple routes,
all of those routes must be absent to trigger the conditional advertisement.
You can optionally specify a sequence number for the advertise route map that
matches the determining route. The sequence number specifies the order in which
the advertise route maps are processed. It indicates the position the specified advertise
route map has in the list of all advertise route maps that are configured for a particular
neighbor within the same address family.
If you do not specify a sequence number, the position of the advertise route map is
considered to be the sum of the current largest sequence number plus five. An
advertise route map with a lower sequence number has a higher priority and is
processed before one with a higher sequence number.
If the route matches more than one advertise route map, only the first matching
advertise route map, based on the sequence, controls the advertisement of a BGP
route.
You can configure a maximum of 50 advertise maps for a given peer or peer group
in an address family. However, the name and sequence number for the advertise
route map must be unique for each entry. BGP applies any policy specified by the
advertise map to the conditionally advertised routes before outbound policy specified
for the neighbor is applied.
The route maps referenced by the neighbor advertise-map command must include
a match ip-address clause. You can also include additional match clauses. All match
commands supported by existing outbound policies are supported. The additional
clauses are useful when you want to match only on a specific route with a specific
set of attributes. Only the permit keyword is acted on in a match clause. The deny
keyword is ignored. Only exact matching of a prefix referenced by exist maps or
non-exist maps is supported. Consequently a range specified by the ge or le keyword
in the prefix list referenced by these route maps is ignored.
Clauses in a route map that include set commands or the match-set summary
prefix-tree command are ignored. To change the attributes of conditionally advertised
routes, you must use outbound routing policy.
If the contents of a referenced route map are changed, the new route map takes
effect automatically.
neighbor advertise-map
â– Use to specify a peer or peer group within the current address family to which
routes specified by a route map are advertised conditionally, depending on
whether a second route map is matched by some other routes in the BGP routing
table.
â– If you specify a BGP peer group by using the peerGroupName argument, all the
members of the peer group inherit the characteristic configured with this
command. This characteristic cannot be overridden for individual members of
the peer group.
â– This command takes effect immediately.
â– Example
Advertising Routes â– 65
Chapter 1: Configuring BGP Routing
To Next Page
Loading...
Need help?
General
