Chapter 4 of 4 · MikroTik MTCRE
OSPF Dynamic Routing
Hello protocol, LSAs, areas, neighbour states, external routes, cost, SPF, stub and NSSA, virtual links, filters.
- 8topics
- 40 minfast track
- 4diagrams and exhibits
Topics in this chapter
Take them in order, or jump to the one you need.
- 1What OSPF Is, Hello Protocol and LSAsLearn what OSPF is, how the Hello protocol finds neighbours, how the link state database is shared, and what each LSA type…5 min
- 2OSPF Areas and Router TypesLearn how OSPF areas divide a network, why the backbone area 0 is special, and what internal, backbone, area border and AS…Diagram5 min
- 3OSPF Neighbour States and DR and BDR ElectionLearn the OSPF neighbour states from Down to Full, why broadcast networks elect a DR and BDR, and how priority and router ID…Diagram5 min
- 4External Routes and Metric Types 1 and 2Learn how OSPF redistributes outside routes, how external type 1 and type 2 metrics are calculated, and how to configure…5 min
- 5Interface Cost, Network Types and NBMA Multicast ProblemsLearn how OSPF interface cost steers traffic, how broadcast, NBMA, point to point and point to multipoint network types differ…Diagram5 min
- 6The SPF Calculation and Shortest Path TreeLearn how OSPF builds a shortest path tree from the link state database with the SPF algorithm, how costs add up, and what…5 min
- 7Stub Areas, NSSA and Area RangesLearn how stub and NSSA areas shrink the OSPF database, how a default route replaces external routes, and how area ranges…Diagram5 min
- 8OSPF Virtual Links and Routing FiltersLearn when to use OSPF virtual links, their configuration and limits, and how routing filters act on OSPF routes and why they…5 min
About this chapter
What this chapter covers
OSPF Dynamic Routing is about how routers learn routes from each other automatically, using the link state protocol OSPF.
It is the longest chapter of the MTCRE guide, with eleven syllabus topics. It starts with the idea and the packets, moves on to areas and neighbours, and ends with the features that control and limit the spread of routes.
Where RouterOS v6 and v7 differ, the pages say so. The configuration menus changed noticeably between the two versions, while the protocol itself did not.
How the topics fit together
The chapter follows the life of an OSPF route, from the first Hello to the entry in the routing table.
The pages build in a sensible order:
- Basics, Hello and LSAs explain what OSPF is and which messages and LSA types it uses.
- Areas and router types show how a network is divided and which role each router has.
- Neighbour states and DR election show how routers become adjacent on shared segments.
- External routes cover redistribution and the two metric types.
- Cost and network types cover path selection and the behaviour of each link type, including NBMA.
- SPF calculation explains how the database turns into routes.
- Stub, NSSA and ranges reduce the information that crosses area borders.
- Virtual links and filters cover the repair tool and the limits of filtering.
Most configuration examples use the RouterOS v6 menus. The v7 differences are noted on the pages where they matter.
How to use these pages
Each topic page has the same shape, so you can skim for what you need.
- What it is: the idea in plain words.
- How it works: the mechanism, with diagrams and example commands.
- What to remember for the exam: the facts to memorise.
- Common mistakes: the classic traps.
- Check yourself: three questions to test your understanding.
Build a lab with at least four routers in two areas. Watch the neighbour states change with /routing ospf neighbor print, read the database with /routing ospf lsa print, and break things on purpose, such as a Hello interval mismatch.
Ready for more practice?
The full MikroTik MTCRE question bank has 417 questions, with timed practice exams and an explanation for every answer.
This study guide is independent and is not affiliated with, endorsed by, or sponsored by MikroTik. Vendor names, certification names and exam codes are trademarks of their respective owners and are used for identification only.