SEO Impact of IPv4 and iPv6?

[Dr-Pete]

Thought I'd see what the asking side of Q&A feels like

We've been hearing for forever that the internet is running out of IP addresses, but I finally encountered the reality of it. I just realized that one of my sites is on a shared IP (hosted by Hosting.com, formerly HostMySite.com). My other sites with them included a unique IP, so I was surprised to discover this. They claim it's due to limitations on their IP allocations.

Hosting.com doesn't have the option to buy a unique IP, but some other hosts do. I noticed, though, that many of them are using IPv6 for the new accounts. Has anyone had practical experience with having an IPv6 address and is there any impact on SEO?

[BradBorst]

Is a shared IP bad?  My site shares an IP on GoDaddy.

[Dr-Pete]

Shared IPs can cause issues with reverse lookups, which could make spiders confuse you with sites sharing that IP. Admittedly, it's rare, but there have been cases of penalties jumping within an IP, for example. I suspect that, as IP sharing grows, Google is getting better about this, but I generally like to avoid it.