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TX Matrix Plus Routing Engine Description


You can install one or two Routing Engines in the TX Matrix Plus router. The Routing Engines install into the Control Boards labeled CB0 and CB1. If two Routing Engines are installed, one functions as the master and the other acts as the backup. If the master Routing Engine fails or is removed and the backup is configured appropriately, the backup restarts and becomes the master.


Nonstop active routing is supported for the TX Matrix Plus router in Junos OS Release 10.0 and later.

The TX Matrix Routing Engine constructs and maintains one or more routing tables. From the routing tables, the Routing Engine derives a table of active routes, called the forwarding table, which is then copied to the line-card chassis (LCC). The Junos OS kernel running on each LCC Routing Engine copies its forwarding table to all Packet Forwarding Engines in the router. The design of the ASICs allows the forwarding table in the Packet Forwarding Engine to be updated without interrupting forwarding performance.

The TX Matrix Plus Routing Engines handle all routing protocols, as well as the software processes that control the interfaces in the TX Matrix Plus router and user access to the TX Matrix Plus router. All Routing Engines in the routing matrix run software processes that control chassis components and system management.

The Routing Engines include the following functions and features:

  • Processing of routing protocol packets—The Routing Engine handles all packets that concern routing protocols, freeing the Packet Forwarding Engine to handle only packets that represent Internet traffic.

  • Software modularity—Because each software process is devoted to a different function and uses a separate process space, the failure of one process has little or no effect on the others.

  • In-depth Internet functionality—Each routing protocol is implemented with a complete set of Internet features and provides full flexibility for advertising, filtering, and modifying routes. Routing policies are set according to route parameters (for example, prefix, prefix lengths, and BGP attributes).

  • Scalability—The Junos OS routing tables have been designed to hold all the routes in current networks with ample capacity for expansion. Additionally, the Junos OS can efficiently support large numbers of interfaces and virtual circuits.

  • Management interface—Different levels of system management tools are provided, including the Junos OS command-line interface (CLI), the Junos XML management protocol, the craft interface, and SNMP.

  • Storage and change management—Configuration files, system images, and microcode can be held and maintained in primary and secondary storage systems, permitting local or remote upgrades.

  • Monitoring efficiency and flexibility—The TX Matrix Plus router supports functions such as alarm handling and packet counting on every port, without degrading packet-forwarding performance.