Static Routing

What this chapter covers

Static Routing is about how a RouterOS router chooses a path for each packet when you write the routes yourself.

It starts with the basic selection rule, then adds load sharing, health checks, policy decisions and the way a gateway is resolved. These are the tools you use to build a reliable multi ISP or multi site network before any dynamic protocol is involved.

The chapter follows the six static routing topics of the MTCRE outline, grouped into four pages.

How the topics fit together

Every packet goes through the same decision chain, and each topic adds one step to it.

The steps build on each other:

• More specific routes decide the winner among routes in one table.
• ECMP lets one route use several gateways at once.
• Gateway forcing and reachability checks make sure the chosen gateway is real and alive.
• Distance orders competing routes, which gives you backup paths.
• Routing marks and rules choose which table is searched in the first place.
• Recursive lookup with scope values explains how a distant gateway is turned into an interface.

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.

Practise on a lab with at least three routers, or on virtual routers. Add a route, print it with /ip route print detail, and watch how the flags and gateway status change when you break a link. Reading that output well is half of the topic.