I have heard that backlinks from other domains are not given much seo value if both domains are hosted on the same server. is it true? if it is true then how about backlinks from websites hosted on the same host but having different IP, those are probably on a different server and their links will count for a natural link from another website? right? (excuse my low technical knowledge about hosting, but I am here to learn after all...)
Some people go to extent of keeping these sites on different class C IP address (not just different IP address). If you have a lot of sites on same IP and they link to each other then it may be bad. Otherwise in case of shared hosting, it's possible that two websites hosted on the same IP link to each other.