Juniper JUNOSE 11.2.X BGP AND MPLS, Configuration Manual

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Use the no version to remove the configuration from the peer group.
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See neighbor allow.
Configuring Passive Peers
You can configure BGP to be passive regarding specific peers, meaning that the BGP
speaker will accept inbound BGP connections from the peers but will never initiate an
outbound BGP connection to the peers. This passive status conserves CPU and TCP
connection resources when the neighbor does not exist.
For example, suppose you preprovision a router before installation with a large number
of customer circuits to minimize the configuration changes you might have to make to
the router. Any peers that do not exist will consume resources as BGP repeatedly attempts
to establish a session with them.
If instead you initially configure the router as passive for those peers, BGP will not attempt
to establish sessions to those peers but will wait until these remote peers initiate a session,
thus conserving CPU resources.
If you configure both sides of a BGP session as passive, then the session can never come
up because neither side can initiate the connection.
neighbor passive
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Use to configure the BGP speaker to only accept inbound BGP connections from the
specified peer and never initiate outbound connections to that peer.
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This command takes effect immediately. If the session is not yet established, BGP
immediately stops initiating outbound connections to the peer. If the session is already
established, it is not bounced regardless of which side initiated the connection.
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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 unless it is
overridden for a specific peer.
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Example
host1(config-router)# neighbor 10.12.3.5 passive
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Use the no version to restore the default condition, permitting the initiation of outbound
connections to the peer.
•
See neighbor passive.
Advertising Routes
Each BGP speaker advertises to its peers the routes to prefixes that it can reach. These
routes include:
• Routes to prefixes originating within the speaker’s AS
• Routes redistributed from another protocol, including static routes
Copyright © 2010, Juniper Networks, Inc. 50
JunosE 11.2.x BGP and MPLS Configuration Guide