Computer tries to access 127.0.0.1?

Infopackets Reader Frances D. writes:

" Dear Dennis,

I have a problem getting my home page as well as other web pages to pull up. My email pulls up, and sends fine. Sometimes, when I access Internet explorer, it tries to connect, but then reports an error message. Other times it will slowly pull up and stop at the half way mark. It tells me it is connecting to site 127.0.0.1. What the heck is site 127.0.0.1? I have contacted my Internet Service Provider and they have told me a number of things to try, but nothing has worked. Is this my computer or is it an Internet problem? "

My response:

It is very doubtful that the problems you are experiencing are a result of a bad Internet connection. If you want to rule this out, you can simply plug in another computer to the same connection and attempt to replicate the problem.

What the heck is site 127.0.0.1?

In a nutshell, every computer connected to the Internet has a unique IP address. Site 127.0.0.1, on the other hand, is a special IP address and actually points to your computer. IP address 127.0.0.1 is also referred to as the local host.

Whenever a web site is accessed from your web browser -- say, www.somewhere.com -- the IP address is of www.somewhere.com is looked up on your own computer using a local 'IP phonebook' file, called the Hosts file. The Hosts file acts as a cache and can define, deny, and allow access to IP addresses of certain web sites.

If IP address does not exist on your local computer via the Hosts file, the browser will redirect to a remote host (such as a proxy server) which stores IPs of web sites that are connected on the Internet.

Side note: A proxy server is "a server between a client application, such as a Web browser, and a real server. It intercepts all requests to the real server to see if it can fulfill the requests itself. If not, it forwards the request to the real server. Proxy servers have two main purposes: improve performance and filter requests." (Source: wmo.ch)

Putting it all together

It's possible that a browser plug-in has gone haywire and your system is trying to self-reference a file or program each time a connection is attempted. This theory may also hold true if a Spyware application (such as a homepage hijacker) has embedded itself into your web browser.

Having said that, the problems you are experiencing may be (but are not limited to) the result of incorrect Internet settings, a firewall, or Spyware. I have a few suggestions below -- although, not exhaustive, it should at least set you on the right track:

1. Check your Proxy Server settings. If you use Internet Explorer, launch IE and then click Tools -> Internet Options -> Connections tab -> LAN settings, and disable any Proxy Servers (if enabled). Close IE and then re-launch.
    
2. Reset your Internet connection settings. If you use Internet Explorer, launch IE and then click Tools -> Internet Options -> Connections tab -> Setup. Follow through the wizard and ensure that your settings match that of your Internet Service Provider.
    
3. Scan your system for Spyware. I personally use Spy Sweeper because it stops Spyware from getting onto my machine *before* it has a chance to do any damage. On the other hand, most freeware Spyware removers (like SpyBot S&D) only clean after a system has been infected. Some Spyware variants can be difficult to *completely* remove from a system and can produce strange results, which is why it's better to protect yourself before hand.
    
4. If you have/had Spyware installed on your machine, your Hosts file may have been affected. This can really mess up your Internet connection when attempting to access particular web sites. To resolve this, backup your Hosts file and replace it with an empty (or valid) one. More info on the Hosts file here.
    
5. If after you've changed your Hosts file and you still have problems accessing a particular web site, temporarily disable your Firewall (if you have one installed) and try again. If the problem disappears, then most likely it is your firewall that is causing problems. Side note: a Hosts file can be used to effectively block internet advertisements found on some web sites. This topic, along with how to set up a free firewall (to stop hackers from accessing your computer) have been explicitly covered in my PC Security Guide. Highly recommended and worth a look!
    
6. If you use Internet Explorer, ensure that your security settings are set properly. To reset your settings to 'default', load IE and go to the Security Tab, and click the default button. Then, go to the Privacy tab and set it to Medium.
    
7. Try another web browser. Mozilla is free: http://www.mozilla.org
    
8. If you used another computer to connect to the Internet and everything works fine and still can't resolve your issue, you can always reinstall Windows as a last resort.