Area Border Router

What Does Area Border Router Mean?

An area border router (ABR) is a kind of router that is located near the border between one or more Open Shortest Path First (OSPF) areas. It is used to establish a connection between backbone networks and the OSPF areas. It is a member of both the main backbone network and the specific areas to which it connects, so it stores and maintains separate routing information or routing tables regarding the backbone and the topologies of the area to which it is connected.


Techopedia Explains Area Border Router

As the name implies, this router is found on the border of each OSPF area, making it the arrival and departure point that distributed information needs to pass through in order to connect to other areas or to the backbone itself.

When arriving, there is a designated route provided by the ABR to move traffic from other areas. When exiting, there is a need for the local area’s ABR to be able to reach a certain destination for the routing information. The main function of ABRs is to summarize sub networks found throughout the OSPF system. It stores many copies of its link-state database in memory when one of the stored copies shows an area where the actual router is connected.


Related Terms

Margaret Rouse

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.