I recently had troubles navigating to my SharePoint 2013 sites. I kept getting 404 errors. In my bindings, I had them set to a specific host header + port + IP address (and each one was unique). I mapped these to my AAM's in SharePoint and registered them with my DNS server. After hours of troubleshooting, I removed the IP address from the bindings (left it blank) and then everything worked. The IP address matched what was in DNS and was set up correctly. I had this same problem with SharePoint 2010 and IIS 7.5 as well.
Can anybody tell me what causes this? I'm hoping its just a simple oversight on my part, and I can in fact bind to a specific IP address if I wish to do so.