What is an area border router?

Area border router (ABR) A router that connects one or more areas to the OSPF backbone. Autonomous system border router (ASBR) A router that is connected to one or more logical entities (AS), usually through an exterior routing protocol such as BGP.

What is the area concept in OSPF?

By definition an OSPF area is a collection of networks, not a collection of routers. A backbone network segment is an IP subnet that belongs to the area identified by 0.0. 0.0. Areas that are not physically connected to the backbone are logically connected by a backbone ABR using an OSPF virtual link.

What is the difference between a backbone router and an AS boundary router?

It stores and operate different routing information related to the topology of the area to which it is attached or to the backbone, as ABR is the member of both the particular areas it is connected and to the main backbone. To make a connection between the OSPF areas and backbone networks, ABR is used.

How many routers are in an area?

Generally, an area should have no more than 50 routers. Areas that suffer with unstable links should be smaller. Number of areas supported by any one router: A router must run the link-state algorithm for each link-state change that occurs for every area in which the router resides.

Why do we need DR and BDR?

DR and BDR serve as the central point for exchanging OSPF routing information. Each non-DR or non-BDR router will exchange routing information only with the DR and BDR, instead of exchanging updates with every router on the network segment.

My cisco book says an area border router is a router that connects to two different areas. The other book says an area border router is the router that connects area 0 to other area say area 2. The 2nd defination makes sense as as the area boder is responsible for inter areas communication.

What is a border router in RPL?

As mentioned in the introduction a border router helps in connecting one network to another. In this example the border router is used to route data between an RPL network and an external network. Till now we have only created the RPL network.

Where can I find the code for the border router?

This webpage is displayed when the IPv6 address of the border router is entered in the browser. Refer to the file httpd-simple.c for the following code snippet The code for RPL border router can be found at /contiki-2.7/examples/ipv6/rpl-border-router. Use the following command to compile the code for the border router

What is a border router in BGP?

A border router is simply an IP router that is charged with the task of forwarding packets between autonomous systems. Each AS that participates in BGP must also have at least one BGP speaker, a router that “speaks” BGP to other BGP speakers in other autonomous systems.