Addon domains and linking

Ive been reading all the threads and info on the net Ive could find, but still not really sure how it really goes.

Lets say I have 1 main domain + 2 addon domains on same hosting provider. All 3 sites are about the same niche but I have created unique content and unique design for each of those sites/domains.

Is it ok to link between all of them? How about between 2 addon sites and then also to main domain, but not from main to addons?

Any info appriciated.

I wouldn't do it. I've been told not to do so as early as 2k6/2k7, if I remember right.

It's already "suspicious", if 3 sites on 1 IP cover the same topic, interlinking them would be even worse.

I'm rather paranoid anyways, but I use several shared hosting accounts with 3 different webspace providers and I neither link between my sites, nor do I target the same keywords/niches on each account/Class-C more than once.

just my 2c :baby09: