Hello everyone, in this tutorial I’ll discuss about types of router and role of router in ospf routing protocol. before we discuss it, we need to known about AS (Autonomous System) it’s a combination of several network that have same configuration, same routing policy and it’s own by one organization or one network operator.

when we configure ospf, of course we must to known about types of router in ospf among others are :

IR (Internal Router)  is a routers that running in one same area. for example if you configure routers in backbone, all of those router in backbone area is a Internal Router.

BR (Backbone Router) is a routers  that have at least one interface which running in area0. If you configure multiple area, every routers connected to area0 can be called as backbone router.

ABR (Area Border Router) is a routers that connecting different area or routers that are bridge between one area to another area.

ASBR (Autonomous System Boundary Router) is a outer router that connecting routing protocol ospf to external routing protocol like BGP,RIP and for bridging router in one AS to another AS.