How do I find out what my IP address is?
Or what does my browser look like to the outside world?
One of the problems with various kinds of network configurations and security is it might be a little hard to judge how your surfing looks to computers on the outside of your network. There are a number of reasons you might want to know for sure, the most common one I run into is debugging. (That and some of my upcoming posts will require that you know how you look to the outside world.) So here you are, your IP address, the way your browser is identifying itself, and some other interesting information your browsers sends via the HTTP Headers so the server knows how best to respond.
Your IP Address
Your browser’s “HTTP_USER_AGENT” string
And a few other header variables for your entertainment
- The domain name of the site your browser is requesting. Once upon a time, when HTTP/1.0 was the standard, and dinosaurs roamed free, web sites were only identified by IP address and port (usually port 80). Once the domain name was translated to an IP address, there was no real use for it. But IPV4 addresses are not infinite. As the internet entered the popular culture and everyone HAD to have a website it quickly became apparent that we were going to run out of addresses. The solution was to transmit the hostname along with the request. That allows the server to host as many sites at the same IP as resources will allow while still identifying the site you are requesting.
- Tells the server if your browser would like to “close” the connection or “keep-alive” assuming there will be further communications with the server. Keep-alive is what you will see most of the time, since each image and support file is a completely separate request. Even if you view only one page, that page will usually consist of multiple HTTP requests.
- These are the types of files your browser will accept. Rather than depend upon file extension, the browser uses something called content type (historically know as MIME type for Multipurpose Internet Mail Extensions.) which has much more flexibility than a simple file extension.
- The types of compression or other data encoding your browser will accept. This allows content to be served in a compressed format to save bandwidth.
- The text encodings your browser is looking for. We don’t all speak english, and some of those Kanji characters are very beautiful but they take a different type of character set to render them. These are the character sets your browser accepts.