How to make relay act as directory cache?

Question

In tor directory protocol, I found that Routers may act as directory caches.

Adding "DirPort 80" in relay's torrc file is right?

or Adding "FetchDirInfoEarly 1" in relay's torrc file is right?

If it is not, what should I do?

Answer 1

You need to add DirPort 80 - it's a preferred port number, but you can use another one if 80 is busy in your case. And the port must be reachable from the outer world via your external IP address. No further configuration is needed so far. FetchDirInfoEarly 1 works sometimes, but - there's no practical neccessity in it as far as I know. My setups, for example, are just using DirPort and it works just fine out of the box.