URL’s Being Cached with a Port Number
A problem i have recently come across was a website that had been cached with a port number in the URL e.g. www.example.co.uk:12345. This was created for a website that used a load balancing server so the developers of the website could access a specific server.
Problems arose when somehow Google started to cache the website with the port number appended in the URL. It wasnt long until the rankings of the website slipped. As you can see having this port number in the URL basically duplicated the website which we all know is not good for SEO.