Nonstop Active Routing Msdp Support - Juniper EX9200 Features Manual

High Availability Feature Guide for EX9200 Switches

Nonstop Active Routing MSDP Support

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Engine neither monitors data MDT flow rates nor triggers a data MDT switchover based
on variations in flow rates. Similarly, the backup Routing Engine does not maintain the
data MDT delay timer or timeout timer. It does not send MDT join TLV packets for the
data MDTs until it takes over as the master Routing Engine. After the switchover, the new
master Routing Engine starts sending MDT join TLV packets for each data MDT, and also
resets the data MDT timers. Note that the expiration time for the timers might vary from
the original values on the previous master Routing Engine.
Starting with Release 12.3, Junos OS extends the Protocol Independent Multicast (PIM)
nonstop active routing support to IGMP-only interfaces.
In Junos OS releases earlier than 12.3, the PIM joins created on IGMP-only interfaces were
not replicated on the backup Routing Engine. Thus, the corresponding multicast routes
were marked as pruned (meaning discarded) on the backup Routing Engine. Because of
this limitation, after a switchover, the new master Routing Engine had to wait for the
IGMP module to come up and start receiving reports to create PIM joins and to install
multicast routes. This caused traffic loss until the multicast joins and routes were
reinstated.
However, in Junos OS Release 12.3 and later, the multicast joins on the IGMP-only
interfaces are mapped to PIM states, and these states are replicated on the backup
Routing Engine. If the corresponding PIM states are available on the backup, the multicast
routes are marked as forwarding on the backup Routing Engine. This enables uninterrupted
traffic flow after a switchover. This enhancement covers IGMPv2, IGMPv3, MLDv1, and
MLDv2 reports and leaves.
Unsupported features: You can configure the following PIM features on a router along
with nonstop active routing, but they function as if nonstop active routing is not enabled.
In other words, during Routing Engine switchover and other outages, their state information
is not preserved, and traffic loss is to be expected.
Internet Group Management Protocol (IGMP) exclude mode
IGMP snooping
Nonstop active routing is not supported for next-generation MVPNs with PIM provider
tunnels. The commit operation fails if the configuration includes both nonstop active
routing and next-generation MVPNs with PIM provider tunnels.
Junos OS provides a configuration statement that disables nonstop active routing for
PIM only, so that you can activate incompatible PIM features and continue to use nonstop
active routing for the other protocols on the router. Before activating an incompatible
PIM feature, include the
nonstop-routing disable
hierarchy level. Note that in this case, nonstop active routing is disabled for all PIM
features, not just incompatible features.
Starting with Release 12.1, Junos OS extends nonstop active routing support to the
Multicast Source Discovery Protocol (MSDP).
statement at the
[edit protocols pim]
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