Multi-site and SEO


I plan to create a few sites which will serve as landing pages and blogs. I want Google to see each of these sites as separate and not related to each other. If I put them all on a multi-site configuration for convenience purposes, will Google know they are part of the same network of sites? If I use the SEO plugin will Google see these sites as related?

Do I need each site to have its own IP address in order to let Google know they are not related?