Practical disadvantages to making ALL OSPF non backbone areas 'stub type' areas?

Started by mrome74, January 27, 2022, 04:55:36 PM

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mrome74

Are there any practical disadvantages to making ALL OSPF non backbone areas some form of stub areas? It seems these areas only ever require default routes to the backbone, and never more.

This seems to only improve convergence, with no downsides. Why isn't this the default recommended architecture?
CCNP, CSIS

icecream-guy

Stub areas cannot be used as a transit area for virtual links.
An ASBR cannot be internal to a stub area.
OSPF allows certain areas to be configured as stub areas, but the backbone area cannot be a stub area.
LSA Types 4 and 5 are not allowed in a stub area.

ref:
https://sourcedaddy.com/networking/stub-areas.html
:professorcat:

My Moral Fibers have been cut.

deanwebb

Just to be clear, are these stub areas, totally stub areas, not so stubby areas, or totally not so stubby areas?

But, to the question at hand, if they're not needing to keep up with external routes from outside OSPF, then, stub 'em. Example: branch office that backhauls all traffic to the datacenter hub. Stub network, there.
Take a baseball bat and trash all the routers, shout out "IT'S A NETWORK PROBLEM NOW, SUCKERS!" and then peel out of the parking lot in your Ferrari.
"The world could perish if people only worked on things that were easy to handle." -- Vladimir Savchenko
Вопросы есть? Вопросов нет! | BCEB: Belkin Certified Expert Baffler | "Plan B is Plan A with an element of panic." -- John Clarke
Accounting is architecture, remember that!
Air gaps are high-latency Internet connections.

wintermute000

There's no real reason not to just do NSSA just in case

With modern networks / CPU / RAM there really isn't a huge use-case (except for terrible WAN conditions etc.) for using lots of OSPF areas. A lot of ISPs will have 100+ routers in the same area lol