Saturday, May 3, 2008

Connect to the internet with authority part 3 (read part1, read part2 )

In this part we are going to do a little trouble shooting. Before that lets go over some details. First look at the diagram below. Get a picture of what is actually happening when you are connected to the Internet. This is a typical home or hot spot setup:
The "You" section means you connecting to the internet. You could be using a direct-to-wire router, or wireless router. You could also be using a modem, or a CELL air card. The Internet Provider is your ISP, he is feeding the configuration down to you directly or to your router, which in turn might feed it to your PC. In the case of a modem or Cell card, you get the configuration directly. The "The rest of the world" is the Internet and all the places you want to get to, including possibly, your office at another location.

Also, I want to recap and explain in a bit more detail what the settings and configuration are and mean: The IP address. This is the address of each computer or node that connects to the Internet. Usually is is in the form of xxx.xxx.xxx.xxx. Each X representing a number. For example, you might have an address of 192.168.1.35 assigned to your Laptop, while that cool web site you regularly visit might be 65.33.33.1. Not to go into too much detail, but I must mention that the 192.168.x.x addresses, those that start with the 192.168 are what are called "private" addresses. That means that you will only see that range of numbers in networks sitting behind the routers and firewalls that you have at home or at work or at a hot spot. You might also see a format that starts like this 10.x.x.x. the 10. is also private. The other one we touched on before, is the loop back 127.0.0.1, but everything else are public addresses.

The Mask. The mask is in the same format, but will be like this 255.255.255.0, or 255.255.0.0 or some other variation. The key to knowing it is a mask, is that you will have at least the first three numbers of 255.x.x.x. The mask determines the network you are on. Each node is part of a sub-net. When you surf the Internet, you are not actually on the Internet, but the Internet is on the other side of your router. The router knows based on your mask whether it needs to send your transmission to the Internet, or if you are just connecting to something inside your sub-net, like your wife's laptop, or a printer, etc.

The Gateway. The Gateway usually is the port on the router that is inside your sub-net. Every router will have at least two ports. One for your sub-net (LAN) and one for the Internet (WAN). The Gateway is your ramp unto the Internet.

The DNS. The DNS (Domain Name Server) is a piece of software, like a database that links an IP address to a name. One word here: There are a lot of DNS servers. Every ISP is required to have at least two, a main one and a backup. They on the other hand connect to other DNS servers. It is like a big upside down tree. They communicate which each other so when you type in www.yahoo.com, they will get the actual IP address for you and then you can get there. The IP to name is much like a phone directory. If the phone directory just had the phone numbers, you could call the numbers and they would work, but you would not know who you are calling. You would have a hard time getting to the person you wanted unless that person told you his number or you would just start dialing until you hit the right number. Pretty impossible. DNS is the phone directory of the internet.

802.11b, and 802.11g. These are the Wireless (Wifi) network protocols. Older routers operated at the 802.11b, slower, but new ones operate at the 802.11g or at both speeds.

WEP/WPA. These are two of the methods of securing a wireless router. WEP uses either 64 bit or 128 bit encryption. WPA uses 256 bit encryption. Open. On the other end, Open means that there is no security set on the router. Most "Open Hot Spots" have no encryption set, so it is easy to hop on those wireless networks. STOP: One word here. I am not covering setting up the router here, just dealing with problems connecting to the Internet using a Wireless connection. Please be aware that any mis-configuration of routers whether wireless or not will cause all kinds of problems. Also your Cable or DSL provider can be having issues that are beyond us trying to fix. So although troubleshooting includes setting up the router correctly, I am assuming that it is, or that it should be.

Basically we are just trying to figure out what is not working so we don't pull all our hair out. Sometimes is a simple fix, other times it is not. Lets start with the obvious, or maybe sometimes not so obvious. Believe me all this has happened to me at one time or another.
  1. Is the radio on? Some laptops have a switch in addition to being able to turn it on and off with the Fn and another key, like the F5 (Thinkpads). Others have software that allows you to turn it on and off or all three. Make sure you know how to turn yours on and off.
  2. On a Wireless Access Point or Wireless Router
    • Is it an open wireless? You have to connect to it, and you will usually have the option to save it as a "preferred" connection. This means if you go back, your computer will have it saved and automatically connect to it.
    • If it is not an open wireless point, do you have the WEP or WPA keys set that are appropriate? This is a killer if you don't have it, you will not be able to connect.
    • Some Networks, maybe yours, use what is called MAC filtering instead of, or in conjunction with the Security Keys. If this is the case, you or whoever is in charge will have to enter that MAC address into the filter of the Access Point or Router. You can get your MAC address by:
The easiest way to do this if the Wireless icon is visible in the System tray, is to right click on it, and select "Status". There are two tabs, on is the General tab where you can actually see the status. Signal strength, the name of the Wireless network you are connected to, and in/out traffic.
This is what the General tab looks like:
    • Select the second tab, the Support tab. Click on the button called "details". On the "Details", the top setting that says "Physical Address", this is the MAC address.
      This is what the Support tab looks like:
      This is what the Details Look like:
      3. Once You are connected to the Wireless Access Point or Router, you will receive your IP address, the Mask, the Gateway, and the DNS configuration.
Wireless on your Computer or Laptop is just not working right What to check:
  1. If you move from place to place, or you often put your machine in standby or Hibernate, try running the "Repair" This attempts to reset your connection to the nearest wireless router that you were connected to, or if not connected to that one, it tries to find a new one.
  2. Turn your Wireless radio off and on. Sometimes I have had to do that despite having everything OK.
  3. Again, if you are connecting to a new network make sure you know if you need a Security key
  4. Also do you see the SSID for the wireless network you are trying to connect to. Some Wireless Routers/Access Points hide their SSID in an effort to enhance security (But it stands to reason, that if you are trying to connect to something you do not see, you already know about it some how).
  5. Check the signal. Sometimes you are connected, but the signal is so weak that you really can't do anything. In that case you are either going to have to move closer, or move the equipment closer to you, or change the angle of the antenna.
You could be connected and still not be able to surf. What to do? Remember the second article. You should know now what it should look like when it is working, so just run through all the steps:
  1. Ping the loop back
  2. Ping the Gateway
  3. Ping DNS
  4. Ping a web site you know the IP address of with the ping -a option, and see if you get the name back.
Sometimes DNS servers flake out, and although you have all the configuration correct, you are still not going to be able to surf. If you can ping an IP address, but the -a switch does not return a name, you can cement the deal of knowing it is a DNS problem by taking that IP address of the Web site you know, and instead of putting that friendly name in your browsers address bar, use the IP address instead. Like this:
  • Instead of http://www.websitename.com
  • Use this: http://111.111.111.111
  • Of course use real ones. Those are just for example. If you come up on the web site, you know it is a DNS problem.
Also, if things are some what quirky, for example: You can get on the Internet but things just freeze, then if it is not a signal strength problem, use the tracert utility. We talked about this in the second article. See if things just seem to drop off some where in the path. This indicates a router problem some where down the line. It might be your ISP or even beyond them. Not much you can do about that. You could call and complain, or go play with the kids or something. VPN I thought I would touch on this again for anyone who has to use it to get to the Work Network. What can you test if you cannot get on? Remember this kind be quite frustrating because you could be on the Internet and everything be going well, but VPN can still fail.
  1. Do you have the right address?
  2. Can you ping that address?
  3. Also, open a DOS or Command Window, and use the following command:
Telnet AddressOfVpn 25 Hit Enter If you get back a black window with the cursor just blinking at the top left, your VPN is working and you should be able to use it. Maybe you are locked out, or something else back at the office is not configured right, or you forgot your user name and password. If you get .... "Could not open connection to the host, on port 25: Connect Failed", then something is keeping you from even getting to it. Remember, the right door must be open. Look back at Part1 of these articles for the Ports for different applications. I hope this has helped. Leave comment, question, suggestion, corrections, additions or whatever. It is all appreciated. Delco

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