Configuring Bgp Networks; Configuring Aggregate Addresses - Juniper NETWORK AND SECURITY MANAGER 2010.4 - CONFIGURING SCREENOS DEVICES GUIDE REV 01 Manual

Configuring BGP Networks

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Documentation

Configuring Aggregate Addresses

Copyright © 2010, Juniper Networks, Inc.
BGP Overview on page 327
Configuring BGP Networks on page 329
Use the BGP network settings to change the route attributes generated by BGP. For each
route you want to change, create a new network entry that contains the IP address and
netmask for the network reachable from the BGP routing instance. Next, configure the
new route attributes for that network. On devices running ScreenOS 6.3, BGP network
supports IPv6. The BGP network settings are displayed in Table 79 on page 329.
Table 79: BGP Network Settings
Parameters Your Action
Check Route Configure how BGP determines route availability for this route:
Availability
Turn Off Reachability Check—When enabled, the BGP routing instance
does not test whether it can reach the specified network.
Check for Same Route—When enabled, the BGP routing instance checks
the prefix entered after the network for reachability; if reachable, the
BGP routing instance adds the network.
Check Route Reachability—Select to direct the BGP routing instance
to perform a test to determine whether it can reach the network you
identified.
Configure Route Configure how BGP determines the route attributes for the specified route:
Attributes
Weight—Select Weight to assign a local preference value to the route
(ScreenOS 5.1 and
that is not advertised to peers. If BGP uses more than one route to a
later only)
destination, the route with the highest weight value is preferred.
Route Map—Select a previously-created route map to apply attributes
for this route. BGP advertises the route with the route attributes specified
in the selected route map.
BGP Overview on page 327
Route-Refresh Capabilities Overview on page 328
Configuring Aggregate Addresses on page 329
Configuring Neighbors and Peer Groups Overview on page 330
Configuring a BGP Routing Instance (NSM Procedure) on page 331
As the number of BGP router addresses grows, each route in the AS requires more memory
and CPU time to process addresses from the routing table. Using aggregation, BGP can
reduce the size of a routing table by summarizing a range of addresses into a single route
entry. Each address range included in the aggregate address is considered a contributing
route within the aggregate address.
Chapter 10: Routing
329