Some pages won't load in portal

I recently started a new job and was given the website to log on to my job's employee portal. I solved the IE compatibility issue but now I have a new issue. I am unable to load some pages. When I click on W2 or Paystub I get a server not found page. The url for those pages are different than the portal's url. The url format is http://xxx.xxxx.local:8001. I've tried adding the url to the trusted sites in IE but nothing helps. I feel like it's a firewall issue on my side but I'm stumped. Any help will be appreciated.