Nonstop Active Routing Bgp Support - Juniper EX9200 Features Manual

Nonstop Active Routing BGP Support

Copyright © 2017, Juniper Networks, Inc.
Nonstop active routing BGP support is subject to the following conditions:
You must include the
path-selection external-router-ID
hierarchy level to ensure consistent path selection between the master and backup
bgp]
Routing Engines during and after the nonstop active routing switchover.
Starting with Junos OS Release 14.1, you must include the
advertise-from-main-vpn-tables
to prevent BGP sessions from going down when route reflector (RR) or autonomous
system border router (ASBR) functionality is enabled or disabled on a routing device
that has VPN address families configured.
BGP session uptime and downtime statistics are not synchronized between the primary
and backup Routing Engines during Nonstop Active Routing and ISSU. The backup
Routing Engine maintains its own session uptime based on the time when the backup
first becomes aware of the established sessions. For example, if the backup Routing
Engine is rebooted (or if you run
backup's uptime is a short duration, because the backup has just learned about the
established sessions. If the backup is operating when the BGP sessions first come up
on the primary, the uptime on the primary and the uptime on the backup are almost
the same duration. After a Routing Engine switchover, the new master continues from
the time left on the backup Routing Engine.
If the BGP peer in the master Routing Engine has negotiated address-family capabilities
that are not supported for nonstop active routing, then the corresponding BGP neighbor
state on the backup Routing Engine shows as idle. On switchover, the BGP session is
reestablished from the new master Routing Engine.
Only the following address families are supported for nonstop active routing.
NOTE: Address families are supported only on the main instance of BGP.
Only unicast is supported on VRF instances.
inet labeled-unicast
inet-mdt
inet multicast
inet-mvpn
inet unicast
inet-vpn unicast
inet6 labeled-unicast
inet6 multicast
inet6-mvpn
inet6 unicast
Chapter 8: Nonstop Active Routing System Requirements
statement at the
statement at the
[edit protocols bgp]
on the backup Routing Engine), the
restart routing
[edit protocols
hierarchy level
45