Global search returns wrong results while searching for IPs or MAC addresses even when the search query is put in "quotes". In this case, Global search would swap out ":" colons for spaces " ".
This is working by design. We can confirm that this is the OOB platform behavior as well and the way Zing search works. Zing only matches documents that contain the exact words in the exact order you specify. An exact phrase search ignores: stop words, punctuation marks, wildcard characters etc. See the documentation for more information Quotation marks allow exact phrase searches.
Since the requirement to search for IP addresses makes a lot of sense we created an enhancement request with the text search development team to consider this as an enhancement in future releases.