ABRs are responsible for summarization and update suppression between connected areas. ABR - Area Border Router, router connected to multiple areas.Area - areas are used to establish a hierarchical network.BDR receives all routing updates from adjacent routers, but it does not flood LSA updates. BDR -Backup Designated Router, hot standby for the DR.The option is used in broadcast networks. DR - Designated Router, chosen router to minimize the number of adjacencies formed.LSA - Link State Advertisement, data packet contains link-state and routing information, that is shared among OSPF Neighbors.The interface is considered a link when it is added to OSPF. Interface - physical interface on the router.Link - link refers to a network or router interface assigned to any given network.No routing information is exchanged unless adjacencies are formed. Adjacency - logical connection between a router and its corresponding DR and BDR.Neighbors are found by Hello packets (unless manually configured). Neighbor - connected (adjacent) router that is running OSPF with the adjacent interface assigned to the same area.These terms will be used throughout the article. RFC 7471 - OSPF Traffic Engineering (TE) Metric Extensionsīefore we move on let's familiarise ourselves with terms important for understanding the operation of the OSPF.RFC 6845 - OSPF Hybrid Broadcast and Point-to-Multipoint Interface Type.RFC 6565 - OSPFv3 as a Provider Edge to Customer Edge (PE-CE) Routing Protocol.RFC 6549 - OSPFv2 Multi-Instance Extensions.RFC 5643 - Management Information Base for OSPFv3.RFC 5329 - Traffic Engineering Extensions to OSPF Version 3.RFC 4577 - OSPF as the Provider/Customer Edge Protocol for BGP/MPLS IP Virtual Private Networks (VPNs).RFC 3630 - Traffic Engineering (TE) Extensions to OSPF Version 2.RFC 3101 - The OSPF Not-So-Stubby Area (NSSA) Option.

RouterOS implements the following standards:

more complex protocol to implement compared to RIP.

OSPF is quite CPU and memory intensive due to the SPF algorithm and maintenance of multiple copies of routing information.

transfers and tags external routes injected into AS.

the logical definition of networks where routers are divided into areas.

updates are sent only when network topology changes occur.

multicast addressing is used to send routing information updates.

The protocol is based on link-state technology that has several advantages over distance-vector protocols such as RIP: OSPF is Interior Gateway Protocol (IGP) designed to distribute routing information between routers belonging to the same Autonomous System (AS).

Network types in ospf