Specifications

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§ block LSP flooding on a per-interface basis (implementation of the mesh
group feature)
§ multiple adjacencies to the same Intermediate System, and path selection
based on the metrics corresponding to those adjacencies
§ intelligent routing between level 1 and level 2 to achieve IGP global routing
optimization - The Open Shortest Path First (OSPF) Internal Gateway
Protocol (IGP) includes support for a backbone area and many stub areas.
Routes are advertised fully between areas, though the way inter-area routes
are distributed within a stub area allows nodes within that area to more
quickly compute shortest paths than if the entire network were routed as a
single area. This support for hierarchy has advantages over IS-IS’s Level
1/Level 2 split where Level 1 routers only know about routes within its Level
1 area. For routes outside of the Level 1 area, Level 1 routers must default
to the closest Level 2 area. So although Level 1 routers usually have less
computation to do to calculate shortest paths, they lose much information
about the entire network. It should be mentioned that policy can be applied
at the Level 1/Level 2 border to control the propagation of routes and thus
control the paths calculated for traffic forwarding.
§ recognize and configure the over-load bit for LSPs - The Juniper IS-IS
implementation honors the over-load (OL) bit in LSPs it receives and factors
that into the path calculations. In addition, Junos can be configured to set
the OL in the LSPs it generates to facilitate IS-IS testing while precluding IS-
IS nodes from calculating paths which transit the Junos router configured
this way.
§ multiple NSAP addresses on the same Intermediate System
§ maximum SPF running interval and periodic SPF running interval - If no
events trigger an SPF for fifteen minutes, Junos will calculate an SPF on its
own. As changes happen that trigger SPFs, this timer is reinitialized. The
Juniper IS-IS implementation also supports the idea of a minimum interval
between SPFs to ensure that the IS-IS implementation doesn’t get stuck in
live-lock.
§ log of adjacency changes that is viewable with the command line interface
§ access to neighbor adjacency information, full link state database, complete
LSP info, SPF calculation statistics and flooding/refresh LSP statistics
§ Per-Interface Password Configuration - This feature can be used for
authentication of ISIS Hellos on a per interface, per ISIS level basis. So one
can configure an authentication password on an ISIS interface, which will be
used to authenticate all ISIS hello packets sent or received on that interface.
§ ISIS Per-Level Password Configuration - This feature can be used for
authentication of ISIS LSP, CSN and PSN packets on either a per box, or a
per level basis. If one configures an authentication password under protocol
ISIS hierarchy, all LSP, CSN and PSN packets are authenticated with that
password, irrespective of the ISIS level of the packet.
3.2.4 BGP-4
The supported Exterior Gateway Protocol is BGP-4. The Juniper Networks BGP-
4 implementation is fully compliant with both the IETF’s specifications and with
the deployed base of implementations in the Internet today. Junos BGP-4 support
includes :
§ TCP's MD5 authentication option
§ communities
§ route flap dampening
§ mesh groups
§ route reflection
§ confederations
§ peer groups
§ regular expressions
§ Multiprotocol BGP (MBGP)
JUNOS BGP implementation supports hundreds of BGP peers.
The Mxxx is very responsive to routing fluctuation and remains stable even in the
face of massive routing churn and that has no impact on the forwarding
performance.
Main characteristics of the Junos BGP-4 implementation are highlighted below :