This is really starting to get on my nerves.

The only DNS server I've been able to get working is Sprints 204.117.214.10

I wanted to try Verizon's but they just wouldn't work for me. I thought maybe I had entered them wrong... ? I just typed in 4.2.2.1, but I thought maybe I should've typed 004.002.002.001?

 

I've been using the 4.2.2.x's. No need for the zero's Churnd.

 

So it would seem Comcast is having troubles again tonight. I messed with the DNS #'s and it seemed take care of the trouble but the speed isn't there.

 

With 4.2.2.1

2005-04-13 22:06:19 EST: 3408 / 348
Your download speed : 3490345 bps, or 3408 kbps.
A 426 KB/sec transfer rate.
Your upload speed : 357206 bps, or 348 kbps.

 

Yeah, I don't know what their deal is. I'm using 4.2.2.2, but I was surprised to know that all I had to do was change the DNS settings only on my computer, even though I'm behind a router. Still works.

 

Yeup.. If you're running DHCP and the router is the server then the norm is that the router/firewall/gateway will be the DNS for the clients on the subnet. That keeps things "simple" and allows a single change to affect all the clients.

But, as you found, there's nothing stopping you from setting a static DNS on he client(s).

Most router/firewall/gateway boxes these days also allow the user to set the DNS address(es) to be set on the DHCP clients. Check the DCHP setup screen on the box, and there should be DNS fields in there. Set the addresses you want to run on the clients, then release & renew each client and you're set.

 

I noticed that too but change them in the router anyways.

Mark, slow down a bit more. So I can just change them in the router and it will be fine? So I could leave the default settings on the clients and change the DNS #'s on the router.

 

Sorry...


Since I don't have a truck hood to draw on , lemme mock up a line-diagram real quick:

PC ----- Router -- |DSL/Cable connection| -- ISP ----- "Internet Cloud"


Given that the PC is configured for DHCP (Dynamic Host Configuration Protocol) then this means that when it boots, it will be depending on someone else to feed it the key elements of TCP/IP configuration information. This is IP address, subnet mask and gateway address. In this case, the "DHCP Server" will be your router, the PC is the "DHCP Client".

Note that "DNS" is not considered a key component of configuration, though it's generally needed since most of us prefer to type in "cnn.com" instead of "64.236.24.4" when we want news. Side note: "DNS" is "Dynamic Naming Service" and it's the way that you get to type in "cnn.com" instead of that number. "DNS" is technically a protocol (a way to exchange information) a "DNS Server" is a machine that's performing the translation from literal name to numbers.


On the "WAN" side of the router (versus the "LAN" side - which is your side), you can also make the choice to use a "static" configuration or DHCP. Most of the time these days, the router will be configured for DHCP as well. The DHCP Server for your router will be boxes at the ISP, and your router will be the DHCP Client.

When the router powers up, it will get it's WAN configuration info from the ISP, and that will include DNS addresses. These are the DNS addressess that the _router_ will use when asked.


Back to your side...

When the PC fires up, it'll get config information from the router, and by default _Windows_ config, it will also ask for DNS addresses. By default in the _router_ config, the router will feed it's own IP address as the DNS address.

This means that when the PC needs DNS information, it treat the router as the DNS server, and since the router isn't really storing any DNS information itself, it will pass on the request to the DNS server it was told to use by the ISP during DHCP configuration.


You can circumvent this process in one of a couple of different ways.

1. You can go into the Windows networking configuration (Control Panel -> Network Connections -> Local Area Connection -> Properties -> Internet Protocol -> Properties -> "Use the following DNS...") and insert DNS addresses there. This will change the DNS server that this one client will use. From that point, when the client needs to make a DNS request, it will pass _through_ your router and head straight to the specified server.
   
   
2. On the router side, within the DHCP section, if you have a spot there for DNS addresses then what you put there will get "served" to all DHCP clients when they gets the TCP configuration info. The net effect of this will be the same as point 1 above.
   
   
3. Also on your router, but this time on the WAN side, some router software will let you override the DNS addresses that the router uses but still get its' basic TCP config info via DHCP. If you change the DNS addresses here, then you would leave the DNS address alone in the router's DHCP configuration. This would let the router appear as a DNS server to all of the clients, but the DNS servers that it uses will be what you specify.

(whew!)

Okay.. There are different reasons to use different methods of controlling DNS servers. In a small home network, it really doesn't make much difference which method you use, but I'll walk through them in the same order as above.

1. Changing the DNS server on a single PC is handy when you want the person that uses that PC to have access to more (or less) addresses than other people on the LAN. Again, in a home network this doesn't make a lot of sense, but the spirit of the ability to do this is when you have an accountant that doesn't need to have access to the development server, and you don't want the developer to have access to the payroll server.
   
   
2. This is handy for the same reason as point 1, but your network is a bit larger and you have "subnets". Accounting and Dev get their own routers and you want to have global control of all clients on each router.
   
   
3. Doing it this way will have an immediate affect on all traffic coming through the router. Point 2 above requires rebooting each PC (or going to a shell prompt on each PC and typing a couple of commands); and depending on the OS, point 1 may also require a reboot. But, if you change the DNS address that the router itself is using, then the effect is global and happens without a reboot of anything.

So... there's the DNS lesson for the day... Hope that helps!

 

DANG!

The only thing I understood was the line diagram.......

Actually, that made a lot of sense and now I feel like a geek for saying that

I had no clue that when you send a request to "cnn.com" it's actually series of numbers. Now I don't feel so geeky.....

 

So, I just opened a browser and typed in 64.236.24.2 and CNN poped up.

THIS IS FREAKIN' ME OUT.......

So the request for cnn.com goes to the Dynamic Naming Service server and changes it to 64.236.24.2 so by keying the server addy you loop the DNS server?

So if you were Rainman you wouldn't need a DNS server, "CNN, definitely 64.236.24.4, definitely 64.236.24.4."

 

oops... I guess I shoulda' started a bit lower in the food chain - sorry.

Okay, the Internet runs on numbers called "IP addresses", "IP" is "Internet Protocol" and it's the root "transport mechanism" of the Internet. "TCP" is "Transmission Control Protocol" and it's an "add-on" to IP which allows for control and routing from point A to point B. This is why the basic protocol is called "TCP/IP", it's actually two things bundled together. And, fwiw, you can have IP without TCP, but not the other way around.

This whole "The Internet runs on numbers" thing comes from needing a way to figure out just _who_ is "point A" and "point B". Computers have an easier time at making sense of numbers than a string of letters, but humans have an easier time at dealing with letters... so there has to be a translation from one to the other.

This is where the DNS server comes into play.

When you type "cnn.com" into a browser, the browser needs to formulate an "HTTP GET" request which is a command that's sent to the web server asking for a page. In this case you want to aim at the CNN web server and you're asking for it's home page.

So, since no one on the 'Net understands "yo CNN, I'm at Ben's house, gimme your home page!" a couple of things have to happen first.

The browser will first ask Windows (in this case) to process a "get address by name" request. This is a programming thing where you send out a name (cnn.com) and get back a number. Deeper in the bowels of the OS, that becomes a "DNS request", which is basically just a block of data sent to a DNS server saying "what's the IP address of cnn.com?".

Things can get "interesting" here... DNS servers are chained together in a hiearchy - and there are a "whole bunch" of them in the world... like 10's of thousands. When Windows makes this request to a server, then it's quite possible that the server doesn't have the answer. DNS servers have a cache for addresses just like your browser does for web pages, and depending on how recently that server was asked for "cnn.com", it may not be there.

If the server does have the answer, then it'll be sent back to the requestor (your Windows machine). If it doesn't, then that DNS server will ask the next server up the chain for an "authoritative response", (basically it's the same request that your Windows machine made of it). If _that_ server doesn't have the answer, then the next machine up is asked, and so-on.

This chain can get kinda' long, especially on a private network. It's only after all nodes of the tree above have been asked, and everyone says "I dunno" that you'd get a "www.lkudshf.com not found, please try again".


Okay... back to the numbers thing again...

In this case, you'll eventually get a response back that "in order to get to 'cnn.com', you want to use IP address '64.236.24.2'". Once the OS has that information, then it passes it back to the browser, and the browser can finally put together it's "HTTP GET". The GET has the IP address of the target server in it (64.236.24.2), as well as the literal name of the domain (cnn.com).

Every machine that exists on the Internet MUST have a _UNIQUE_ IP address. If they didn't, things could get confusing 'cause DNS wouldn't work right. You might ask for cnn.com, but if the IP address was also in use by a gardening site, you could be looking at mole traps instead of the latest political issues.

The "unique" thing is a bit interesting though... If you do the math to figure out how many IP addresses you can have (there are 4 "octets" in an address, and each octet can range from 0-255 with a couple of exceptions) then you'll see that there are clearly more machines on the 'Net (and reserved address blocks) than there are addresses.

The current way of dealing with this is through something called "NAT", or Network Address Translation. This allows for multiple machines to sit behind one IP address. For example, I have 7 machines here at home, but there is only one IP address into the house. Just like you have two machines on one IP address. (explaining how NAT works is a bit out of context...)

In our cases, "NAT" is being done by our routers, and this makes sense for the _client_ side, but doing this on the server side is a bit more interesting.

Say you were at work and wanted to get to your desktop machine at home. Since you have two machines on one IP address, it gets a bit tricky to deal with. There are games you can play with "port mapping" but that doesn't work well with DNS. What you would do is setup support for virtual servers/domains.

This is where you define a process (sometimes a dedicated machine) that will sit on one IP address and masquerade as a web server. It will look at the HTTP GET request coming in, (which, remember, got routed to the IP address) and disect it to get the "hostname" (the "cnn.com" part) out of it. It will then take that name and use it to figure out which server hosts that site, then forward the request on. In this fashion, it acts just like a router where it's playing traffic cop and making sure that data gets to where they're supposed to go.

And... this is also how "load balancing" works. "cnn.com" isn't one server, there are MANY MANY machines that service requests for the CNN web pages. The machine that's at the 64.236.24.2 address is a front-end that takes the inbound request, looks over it's shoulder for the least busy machine and then forwards it on to be processed.


Here's a bit of fun in example...

Open your browser, type in "midiwall.com" and hit ENTER. You'll recognize the page. The IP address of that server is 198.144.200.122, so now jam that address into a browser and... what'd ya' get?



That's an example of a virtual server (actually a virtual domain). The ISP that hosts my site uses a single IP address to host many domains. The machine at the front end looks at the HTTP GET to figure out what site it should serve up. If you request a domain by name ("midiwall.com") then it knows what to do. But, if you take away that info, then it's lost and you get the default root server page.

You can also see it in action this way... type in "midiwall.com/4Runner/", and you get my 4Runner page, but if you try "198.144.200.122/4Runner/" you'll get a 404 error (page not found) since the "4Runner" directory isn't on the root server, it's in the midiwall.com virtual server.



The short form of all this is that nothing happens on the Internet without an IP address. It may look like it does, but it's all smoke and mirrors to make the user's life easier.

 

Anybody still having problems? Mine are particularly at night. The server will periodically go down, and switching to another DNS doesn't always work. I'm getting sick of this. I just got my bill for the full price, and you can bet that I'm calling Comcast to get it lowered, since it's been off for at least half the month.

 

I called Comcast and complained about the 4/7 outage and the took that day off my bill. I called this past Monday (4/18) and complained about the service or lack thereof, my girlfriend was taking an online quiz and it went out on her. I switch between DNSs but I feel that I shouldn't have to, I told Comcast that.

 

Comcast reported they would pay 1.64 USD per day for the lack of service. HOWEVER, you must call them. I have been online with comcast helpdesk. It's been so awful that I won't do it again. Once instance the person told me to empty my internet explorer cache and cookies to solve the problem. Another, required me to provide social security number, the last payment amount and bill number before moving forward. OMG, Comcast has the WORST customer service that I have ever seen. Please note: if you call Comcast you end up Canada. There's some nice folks up their but, they're hands are tied by a process of dead wood and poor management.

 

really then they owe me a few bucks

 

Well, this should confuse the Comcast issue some more...

"About one in every ten U.S. cable subscribers will get a new provider as the result of a $17.6 billion deal unveiled Thursday in which Comcast Corp. and Time Warner Corp. agreed to jointly buy Adelphia Communications as well as swap some of their own cable customers."
http://money.cnn.com/2005/04/21/technology/adelphia/