LochnarITB wrote:
OK. In a nutshell, when you tell your browser to retrieve a certain URL, there are a number of HTTP protocol headers that the server sends before the data. Examples would be the type of data that this file is (HTML, JPEG image, MP3 audio, etc), the size of the file, an alternate location for the file (the Location header that I mentioned), how often it should automatically reload the page, whether and for how long it should cache the page, and so on. In general, headers tell the browser what to *do* with the data once it arrives. A surprisingly large majority of all web-server problems are caused by incorrect HTTP headers, since the vast majority of server operators know next to nothing about them or even that they exist.
As for how to see them, you need some kind of add-in program, as browsers hide that sort of technical data from the user. I know of at least four ways to see HTTP headers, though:
This Utility which patches into IE on Windows.
A network packet sniffer such as this one.
A software proxy that can log traffic that passes through it.
The Lynx text browser, which accepts a command-line parameter -HEAD to show just the HTTP headers sent by a server.
Mozilla/Firefox probably has a plugin/extension to do it too, but I don't keep up with developments on that.
I'm no expert, but from what I've seen, their purpose is pretty much as an ticket if you're trying to get entry into the networking field or to change careers. If you've got experience in the field, any employer is going to look at that before any certification. But if your previous professional expertise is in, say, real estate or truck driving, you need something to show that you have some competency in a new field.
Hope that helps.
Quote:How do you watch what comes down the pipe to see what the lounge server is sending down the line to you?
OK. In a nutshell, when you tell your browser to retrieve a certain URL, there are a number of HTTP protocol headers that the server sends before the data. Examples would be the type of data that this file is (HTML, JPEG image, MP3 audio, etc), the size of the file, an alternate location for the file (the Location header that I mentioned), how often it should automatically reload the page, whether and for how long it should cache the page, and so on. In general, headers tell the browser what to *do* with the data once it arrives. A surprisingly large majority of all web-server problems are caused by incorrect HTTP headers, since the vast majority of server operators know next to nothing about them or even that they exist.
As for how to see them, you need some kind of add-in program, as browsers hide that sort of technical data from the user. I know of at least four ways to see HTTP headers, though:
This Utility which patches into IE on Windows.
A network packet sniffer such as this one.
A software proxy that can log traffic that passes through it.
The Lynx text browser, which accepts a command-line parameter -HEAD to show just the HTTP headers sent by a server.
Mozilla/Firefox probably has a plugin/extension to do it too, but I don't keep up with developments on that.
Quote:A second question of you, or anyone who cares to comment, do you know of and what is your opinion of Network+ and Server+ certification? Are they valuable for the person and to future employers?
I'm no expert, but from what I've seen, their purpose is pretty much as an ticket if you're trying to get entry into the networking field or to change careers. If you've got experience in the field, any employer is going to look at that before any certification. But if your previous professional expertise is in, say, real estate or truck driving, you need something to show that you have some competency in a new field.
Hope that helps.