I am a Internet marketing professional and wish to know 1: what directory submission on the same IP address of any site will penalized by search engine or not ? 2: if we have get back-links on same IP Address of our website then penalized for search engine or not ?
You should always strive for a natural link profile. If a large proportion of your links are from the same IP then Google can assume that your links were artificially created. On the other hand, they may decide to not count the links. Here is some info on natural links.
Having multiple directories on the same IP is not a problem according to Google, read this article You do however want to stay away from directory farms run off the same IP address or server. Recently Google has stated that too many of the same type of sites on a server could post a red flag.