Enabling Lenient Behavior; Configuring Promiscuous Peers And Dynamic Peering - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - BGP AND MPLS CONFIGURATION GUIDE 2010-10-12 Configuration Manual

Enabling Lenient Behavior

neighbor lenient

Configuring Promiscuous Peers and Dynamic Peering

Copyright © 2010, Juniper Networks, Inc.
host1:vr1(config-router-af)#neighbor 192.168.1.158 activate
Use the no version to indicate that routes of the current address family are not to be
exchanged with the peer. Use the default version to remove the explicit configuration
from the peer or peer group and reestablish inheritance of the feature configuration.
See neighbor activate.
If you have configured some or all neighbors to be in the multicast or VPN-IPv4 address
families, you can quickly configure all neighbors to be part of the IPv4 unicast address
family by issuing the bgp default ipv4-unicast command.
You can use the neighbor lenient command to enable the BGP speaker to attempt to
recover from malformed packet errors and finite state machine errors generated by a
peer. If BGP can recover from the error, it logs a warning message and attempts to
maintain the session with the peer. The normal, nonlenient behavior is for the BGP speaker
to send a notification message to the peer generating the error and to terminate the
session. By default, lenient behavior is disabled.
Use to enable a BGP speaker to be more tolerant of some errors generated by a peer,
such as malformed BGP messages or finite state machine errors.
The speaker attempts to recover from the errors and avoid bringing down the BGP
session with the peer.
Lenient behavior is disabled by default.
Example
host1(router-config)#neighbor 10.12.45.23 lenient
Use the no version to restore the default condition, disabling lenient behavior.
See neighbor lenient.
You can use the neighbor allow command to enable a peer group to accept incoming
BGP connections from any remote address that matches an access list. Such a peer
group is known as a promiscuous peer group; the member peers are sometimes referred
to as promiscuous peers.
Promiscuous peers are useful when the remote address of the peer is not known ahead
of time. An example is in B-RAS applications, in which interfaces for subscribers are
created dynamically and the remote address of the subscriber is assigned dynamically
from a local pool or by using RADIUS or some other method.
BGP automatically creates a dynamic peer when a peer group member accepts the
incoming BGP connection. Dynamic peers are passive, meaning that when they are not
in the established state, they will accept inbound connections but they will not initiate
Chapter 1: Configuring BGP Routing
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