Linking from different IP, but same server, how much it can hurt?

[_Z_]

Example,

• Have a site on 173.194.33.51 and site on 173.194.33.52, same server, different IP addresses, same network subnet.

• Make one link from site residing on 173.194.33.51 to site on 173.194.33.52

Can this hurt?

Can it be beneficial if site on 173.194.33.55 has good PR?

[RyanKent]

Both URLs share a C-block so Google would likely discount the link. It shouldn't hurt, but it is highly likely it wont help either.

Obtaining IPs on the same server with different C-blocks would be an improvement, but you are moving into the direction of taking actions specifically to manipulate search rankings aka black hat seo.

[_Z_]

Would it be better to make it nofollow if the link can bring traffic to the site?

[RyanKent]

Not at all. If you know the target site is reputable (i.e. is not likely to be penalized) then leave the link as followed. The primary reason to add nofollow to an external link is to protect yourself from being penalized for linking to a "bad" site.