Topic: Networking Basics

[Bonk]

There is clearly a need for a thread like this. I'll work on filling it in over the next while.

Topics to be covered:

• Cable vs ADSL vs Dial-Up vs Satellite
• Routers vs Hubs
• LAN vs WAN
• DHCP
• DNS
• Static lan configuration
• NAT / port forwarding
• why pings should be allowed
• UDP and TCP
• Latency vs Bandwidth
• Software firewalls, how to use them and when.
• Where to find manuals and why you should read them in full.
• Workgroups, Domains and Subnets

Those who have the expertise, feel free to help out and correct me where I'm wrong and suggest additional topics. I don't have the patience for working on it today, but this needs to be done.

[toasty0]

I am very excited about this thread. I look forward to reading your tutorials, Bonk.

Now you all know I'm a very rabid anti-pinning person, but, man oh man, if any thread ever calls out for pinning, this one does.

[Sethan]

Step 1) You get a broadband connection at home.

Step 2) After following the "simple instructions" (which load a CD's worth of unneccessary system tray apps onto your computer), it doesn't work.

Step 3) You spend 3 hours on the phone trying to get it fixed.  The first hour of that time is spent on hold, the remainder with a support guy in India who barely speaks English and is reading off a script.

Step 4) Since it still doesn't work after the support call, you call in a friendly neighborhood computer tech.  He gets it up and running in 15 minutes (or 2 hours if you are running WinXP), then asks if you are planning to buy an antivirus program and a router.  Then he explains why you should get them.  Your eyes glaze over.  You decide against the extra expense, and pay him for his time.  He hands you his card with this cell phone number on it, walks away smiling, and you don't understand why.

Step 5) Shortly after installing AOL, Yahoo, Kazaa, Gator, and Bonzi Buddy onto your computer and surfing a few porn websites, your computer suddenly slows to a crawl, and the only web page it will pull up is on Czechoslovakian vegetable porn, featuring women who look suspiciously like men.

Step 6) You call your friendly neighborhood computer tech back on his cell.  "It stopped working!"  He arrives in record time (he's been sitting in your driveway since he left the first time), and tells you he'll have to take the computer to fix it.  $$$

Step 7) He brings the computer back two days later with antivirus installed on it, explains that some of the programs you had installed were bad (and why), and tells you again you really ought to get a router.  Your eyes glazed over once he started talking, and you stopped listening until he mentioned the price of the router.  You decide against the extra expense, and write him a check with a large number on it.  He walks away whistling...

Step 8) You discover that AOL, Yahoo, Kazaa, Gator, and Bonzi Buddy are not on the computer anymore, so you reinstall them...

...and somewhere your friendly neighborhood computer tech is grinning ear to ear.

[Bonk]

   Good one Sethan!    Czech veggie porn... <chuckle>

This is what I aim to help to prevent, just not today, but I will make an effort to fill the above outline in as soon as I can to avoid repeating myself. And yes Toasty0, once I have filled in some content this thread will be most worthy of a sticky.

[Darth Sidious]

Or if the person getting the computer support if the tech's girlfriends mother - add a threat to install a random distro of linux the next time i have to fix the pc again.

Step 1) You get a broadband connection at home.

Step 2) After following the "simple instructions" (which load a CD's worth of unneccessary system tray apps onto your computer), it doesn't work.

Step 3) You spend 3 hours on the phone trying to get it fixed.  The first hour of that time is spent on hold, the remainder with a support guy in India who barely speaks English and is reading off a script.

Step 4) Since it still doesn't work after the support call, you call in a friendly neighborhood computer tech.  He gets it up and running in 15 minutes (or 2 hours if you are running WinXP), then asks if you are planning to buy an antivirus program and a router.  Then he explains why you should get them.  Your eyes glaze over.  You decide against the extra expense, and pay him for his time.  He hands you his card with this cell phone number on it, walks away smiling, and you don't understand why.

Step 5) Shortly after installing AOL, Yahoo, Kazaa, Gator, and Bonzi Buddy onto your computer and surfing a few porn websites, your computer suddenly slows to a crawl, and the only web page it will pull up is on Czechoslovakian vegetable porn, featuring women who look suspiciously like men.

Step 6) You call your friendly neighborhood computer tech back on his cell.  "It stopped working!"  He arrives in record time (he's been sitting in your driveway since he left the first time), and tells you he'll have to take the computer to fix it.  $$$

Step 7) He brings the computer back two days later with antivirus installed on it, explains that some of the programs you had installed were bad (and why), and tells you again you really ought to get a router.  Your eyes glazed over once he started talking, and you stopped listening until he mentioned the price of the router.  You decide against the extra expense, and write him a check with a large number on it.  He walks away whistling...

Step You discover that AOL, Yahoo, Kazaa, Gator, and Bonzi Buddy are not on the computer anymore, so you reinstall them...

...and somewhere your friendly neighborhood computer tech is grinning ear to ear.

[KBF-Kurok]

 cant wait for this thread. to start filling out.

[NJAntman]

Step 5) Shortly after installing AOL, Yahoo, Kazaa, Gator, and Bonzi Buddy onto your computer and surfing a few porn websites, your computer suddenly slows to a crawl, and the only web page it will pull up is on Czechoslovakian vegetable porn, featuring women who look suspiciously like men.

Well, since I got broadband I thought I'd seen it all! Any, umm.. coucg, cough... links?

Seriously though, great thread. I'm thinking on installing a network card to connect the Tivo to my broadband connection; I'll be watching this thread closely.

[NJAntman]

I've been digging into the details necessary to hook up a wireless router and put an adapter on the Tivo, and about the only progress I've made is creating a hole big enough to bury the idea in and just walk away. Holy crap, what a hassle!

The recommended adapters are either not for sale (new) anywhere or if they are available the sellers cannot tell me which version. The version is critical since according to the official site and assorted forums I've visited the adapter may very well be a supported model but different versions are incompatible. And of course none of the online sellers can be certain which version is in tht e box they are selling.

Anyone out there know of a seller (new) that provides good info, like right down to the specific version of the adapter being sold?

P.S. Even the Tivo online store couldn't tell me over the phone wether the one they are selling is the specific version needed. They didn't even know the difference in versions that their own site was calling for. Oh my aching brain.

[FA Frey XC]

There is clearly a need for a thread like this. I'll work on filling it in over the next while.

Topics to be covered:

• Cable vs ADSL vs Dial-Up vs Satellite
• Routers vs Hubs
• LAN vs WAN
• DHCP
• DNS
• Static lan configuration
• NAT / port forwarding
• why pings should be allowed
• UDP and TCP
• Latency vs Bandwidth
• Software firewalls, how to use them and when.
• Where to find manuals and why you should read them in full.
• Workgroups, Domains and Subnets

Those who have the expertise, feel free to help out and correct me where I'm wrong and suggest additional topics. I don't have the patience for working on it today, but this needs to be done.

Handled in the following :

Cable vs ADSL vs Dial-Up vs Satellite

More to come...

Routers vs Hubs

Definitions:

ROUTER: A device that determines the next network point to which a data packet should be forwarded enroute toward its destination. The router is connected to at least two networks and determines which way to send each data packet based on its current understanding of the state of the networks it is connected to. Routers create or maintain a table of the available routes and use this information to determine the best route for a given data packet

HUB: The point on a network where a bunch of circuits are connected. Also, a switching node. In Local Area Networks, a hub is the core of a star as in ARCNET, StarLAN, Ethernet, and Token Ring. Hub hardware can be either active or passive. Wiring hubs are useful for their centralized management capabilities and for their ability to isolate nodes from disruption.

So, the difference? A router must have TWO networks to function, a HUB simply re-transmits the packet on all available nodes.  A router routes the packets to and from separate networks.

ADDENDUM: Perhaps a more apt comparison would be the following:

HUBS VS SWITCHES

I'll add that on when I'm done with this list.

LAN vs WAN

LAN : Local Area Network. The term LAN describes a local network. This LAN can consist of one network, or seperate networks connected via a router.

WAN: Wide Area Network. This is a network that spans a large geographical distance and interconnects two or more LANS or MANs. The internet is the largest WAN in existance.

ADDENDUM : MAN - Metropolitan Area Network: A data network designed for a town or city. In terms of geographic breadth, MANs are larger than local-area networks (LANs), but smaller than wide-area networks (WANs). MANs are usually characterized by very high-speed connections using fiber optical cable or other digital media.

DHCP

DHCP : Dynamic Host Configuration Protocol (DHCP) is a communications protocol that lets network administrators manage and automate the assignment of Internet Protocol (IP) addresses in an organization's network. DHCP allows devices to connect to a network and be automatically assigned an IP address. Essentially this allows for better management and utilization of IP addresses, as well as lowering costs associated. Using DHCP, a client connects to the DHCP server and asks for an IP address. This is set on the scope, along with other information such as DNS servers, NTP servers, and WINS server addresses. The client then receives a IP address, and the DHCP server records this "registration" of the indicated IP address in it's table. It also records the time / date when that registration is tombstoned, or revoked if the client doesn't "check back in" (this is specified in the DHCP server options, not to be mistaken as included in the scope options) within the set time period (usually 1-7 days). The DHCP client will usually actually check for the client on the network 1/2 of the expiry set - so if it's set for 7  days, then in actuality it will perform it's first check in 3 1/2 days. This allows the maximum usability of a given subnet without wasting any IPs - especially valuable for ISP's who recycle their IP addresses constantly.

DNS

DNS stands for Domain Naming System, and is the process used to translate IP addresses into human friendly web addresses. Think of your IP address similiar to your mailing address. The Postmaster would have a helluva time delivering mail to your house if every other house on the block had the same mailing address. Thus, each and EVERY device on a network MUST have a UNIQUE IP address. That being said, it would suxxors to have to type in "http://216.109.112.135/default.htm" to access www.yahoo.com, and it would make Host Headers used in website hosting useless.

Thus, DNS was born. DNS translates those human friendly names like "www.dynaverse.net" into the actual IP address and then connects to the authorative DNS server for that root domain to get the necessary information regarding the sites/data available there. Let's track the actual process utilizing D.Net as the target.

1. User types in "www.dynaverse.net" in the browser URL window. The browser looks at the current TCP settings and obtains the DNS servers the client is mapped to. Before querying those servers, it checks it's cache to see if it already has looked up that URL (Uniform Resource Locator) and translated it to an IP address. If it has, skip to step 4.

2. System queries the DNS servers the client's TCPIP stack has assigned to it, either via DHCP or statically assigned for the IP address of the site. IF the DNS server does not have the information in IT'S cache, then it queries the ROOT Servers, of which there are 13, to find out what DNS server is authorative for the DNS ZONE. It then sends a query to the authorative server for the requested resource.

3. The authorative server responds, the client machines transparently maps that to the URL, and the browser contacts the IP address of the resource as stated in the DNS ZONE for a webserver at port 80.

4. The webserver then replies back, a connection is made, and you are surfing the website !

I'll include a zone dump when I am in the office for D.Net so you can see what a DNS Zone looks like.

Static lan configuration

Simply put, this is when a user or Administrator specifies the information for the TCPIP stack, I.E. Default Gateway (the path out of the network to other networks), DNS servers, WINS servers and IP address. Having a statically assigned IP address of course means you're not using DHCP. Servers are almost always statically assigned IP's as having servers aquire IP addresses via DHCP would render DNS useless.

NAT / port forwarding

NAT stands for Network Address Translation. Port forwarding is actually a different subject, I will cover both here.

NAT: This is what allows a home user to have more than one computer behind a ROUTER while using only 1 IP address. Essentially, it's like this:

The Router has a external, or WAN interface. This is a single IP address usually obtained via DHCP from the IP scope of the users ISP. Since Routers, by our above definitions, require two networks to operate, NAT creates those two networks by utilizing non-routable address blocks, such as 10.0.X.X, 192.168.X.X, or 172.16.X.X.  These non-routable classes will NEVER be on the internet, as they are reserved for internal private networking.  The end user would then set up the Router's internal , or LAN scope. By default on most routers this is the 192.168.X.X subnet. Then, the internal network gets it's IP address via DHCP from either the router or a local DHCP server, and specifies the router as the default gatway for traffic OFF the 192.168.X.X subnet.  Thus, you can have up to 253 computers on the internal network - the 1st address and last address of any given subnet is ALWAYS reserved for the network address and broadcast address, respectively. As a packet goes out from the internal network , the router records the IP address of who it was from, where it's going, and waits for a returning packet that is addressed to the "original sender". It then routes the packet to the correct internal IP address of the client whom sent the data. 

Thus, as one could imagine, you've now allowed many many internal clients to connect to the internet behind ONE IP address on the router. We'll leave the positives and negatives to this approach for a later discussion.

Port Forwarding

WIP

[Bonk]

Thank you, thank you, thank you Frey! 

I'll admit I have been very slack on this and it looks like you could do a better job anyway. I'll try and add some content soon.

[Skawpya]

well ran into a weird bug involving networking I think.

using a 1520 actiontec dsl modem, used it for over a year with no complaints about it (said complaints where with the isp and phone company)

recently got a new computer assembled, found that pre activation, I could access the net normally with it using a computer - ethernet - dsl modem pathway.

of course due to activation worries I had to buy a new windowsxp professional disk with activation key. Did so, found an apparent deal on amazon, vender with 4.5 starts offering for 150.

First sign of trouble was that confirmation email came from china

second sign of trouble, I did an upgrade using the new disk, and then a hd wipe followed by fresh installation.

In first case me and the isp networking person did everything we could think of, but the end result was that the computer was acknowledged to exist in the network that resulted but it could not access the internet in anyway. The clean install resulted in the same problem.

Tonight, I'll be rewiping the hd, using my old xp disc to install, and then using the key from the new disk only to get the activation finished.

My question is whether is a way that chinese dealer could have possibily dissabled the xp's means of connecting to the internet, likely because dozens of windows xp discs where made with that same key, making activation something they did not want to happen.

[The Bar-Abbas Anomaly]

 

That's very unlikely, Skawpya.  More likely is something simple like your NIC requireing a driver not available on the XP CD or something simple like that.

[Overmind]

Well, i have a little situation here.
I have internet connection through a LAN.
To access the internet, we use and internal IP (like 11.1.1.125).
And we do that through the proxi server (witch is 11.1.1.1).
Now, browsers work great, downloads too, yahoo & msn mess; anything...
...except games.
No server is able to connect to the master servers.
(CS, UT, RA, nothing).
If I try to connect directly to ip (like connect 222.222.222.222, witch would be a game server), the game does not connect.
Unreal Tournament for example does not find the master server.
And removing the proxy (11.1.1.1.) did not help. Further more, nothing works if I remove the proxy.

So, any thoughts on how can I play something online ?

Btw, Himatachy does not work either (connection says invalid ip: 0.0.0.0.).

[FCM_SFHQ_XC]

Well here is some information on Cable vs ADSL vs Dial-Up vs Satellite.. might add more to it later
Cable vs ADSL vs Dial-Up vs Satellite

Cable: Cable is considered one of the fastest internet services out there using a hybrid of fiber optic cable and UTP[Unshielded Twisted Pair] or STP [ Shielded Twisted Pair] Cable, but can use pure fiber optic or pure UTP cable. Cable has a huge bandwidth allowing for users to reach speeds of nearly 10 Mbps(1 MB/sec). However, Cable shares its bandwidth with all users in a certain geographical region. As a result during peak times speeds of cable can be nearly cut in half! Also, with lots of users using the same bandwidth it is easier for local security braches to occur. Overall though cable has a high up time and is fairly reliable. Cable does not come though phone lines and is avaliable through a cable TV service provider.

ADSL: Digital Subscriber Line. DSL uses the same media as Dial Up connections and phone lines. DSL links people to the Internet by sending high-speed signals through their existing telephone lines. In order to be eligible for the service, you need to live near a phone company's CO (or "central office," the box where the phone line from your house connects to the phone company's gateway for your neighborhood). DSL operates as a separate connection so there is no loss of bandwidth so long as there is no real problem with the media. Poor termination(not connected correctly with the untwisting of the wires), longer then normal transmission lengths to the CO box, and RIF all reduce the bandwidth and speed some. DSL does not require fiber optic cable, but fiber optic can allow for better transmission rates. The Closer to a CO box you are the faster your connection is. DSL is the 2nd fastest connection type, with very low ping rates. DSL speeds are continuing to improve with a maximum of 8 Mbps currently.

Dial-Up: Dial Up, also know as 56K is one of the oldest connections around. Dial Up uses a standard telephone to transmit data just like a regular telephone. However, it is extermly vunerable to noise in the phone line. Dial up transmits at a maximum of 56 Kbps, and the ping is usually in the 200's. Dial-Up also blocks the phone from recieving incoming calls or making a call. Standard UTP or STP cable is used. Dial Up is one of the cheapest and least expensive internet services though.

Satellite: Satellite is one of the most expensive internet services around and also has one of the highest pings. Pings are usually within the 1000's or low 800's, and operates like a wireless LAN. The Satellite Dish transmits information to the Satellite in orbit then back down to the ISP. Information is not nearly as secure and is most likely to get degraded. It does reach speeds though of nearly 768 Kbps, and can be a good alternative if Dial Up is too slow. Satellite is also available anywhere where there is a view of the sky. Trees and other solid objects, along with radio and EM waves can interfear with the transmission, further degrading any signal transmitted

[Sirgod]

Have I mentioned how much I had Networking.

My old router went out on me , so while the wife was in town, I asked her to pick me up another wireless G router. When she was there with her sister, her sister asked what she would need to get her 3 PC's on a wireless lan, and still be able to put the kids XBox online. I told her all she needed was two wireless cards, "G" of course.

anyway, after much fighting, broken fingernails, alot of saliva dripped into various keyboards, I finally got everything set up.

HEre's where I went wrong, Everything I had used prior was Linksys. They bought, and I didn't even think of it, Belkin routers and cards.

I had never worked on a Belkin networking product before, and It took alot of cussing to get them to talk with each other on so many machines.The wireless cards for example, have about 6 differant versions for the same product number ie. F5D7000 ver a ; wer b; etc.

And of course every single card they had was a differant version. The router was the easiest thing to install after all that. Now though, They are asking me how to combine our two seperate LAN's together for File sharing , Gaming with the kids etc.

BTW. The last game consule I ever hooked to the internet was the old Dreamcast. The Xbox 360 is so much easier, and even using the controler to type, It's far more responsive then I thought it would be.

Stephen

[Commander Maxillius]

Problem.

I am posting this on my brand-new Mac Mini on a low-speed broadband connection (512k).  It works well, and without a hitch.  Totally no problems to get it online.

The machine I'd like to play SFC with y'all on is another matter entirely.  Win XP home SP1.  The damn thing won't get on at all.  Not with the ethernet car, and not with the cable modem's USB option.

I own a router, a Linksys BEFSR41 ver.3, and I need a windows machine to set it up.  I own 2, and NEITHER ONE OF THEM can get to the damn thing.  The Win98 machine's NIC card is broke, so that's the fault with that, but the XP machine I just got from my sister and it was her main machine: it obviously works.

I need some help!!!

[The Bar-Abbas Anomaly]

Problem.

I am posting this on my brand-new Mac Mini on a low-speed broadband connection (512k).  It works well, and without a hitch.  Totally no problems to get it online.

The machine I'd like to play SFC with y'all on is another matter entirely.  Win XP home SP1.  The damn thing won't get on at all.  Not with the ethernet car, and not with the cable modem's USB option.

I own a router, a Linksys BEFSR41 ver.3, and I need a windows machine to set it up.  I own 2, and NEITHER ONE OF THEM can get to the damn thing.  The Win98 machine's NIC card is broke, so that's the fault with that, but the XP machine I just got from my sister and it was her main machine: it obviously works.

I need some help!!!

I'm pretty sure your Mac should be able to talk to this router... Just open a browser window and point it to the router (or gateway's) address, such as 192.168.0.1 or whatever your router/gateway is.

This should pop up a login window and allow you to enter your admin username/password and configure the device directly without using the CD that came with it.

[NJAntman]

Here is silly question but I'll ask it anyway..... can I have a network with one machine running Win Vista and laptop running WinXP?

I currently have a Linksys WRT54GS router and HP printer attached to my XP SP2 desktop with both a laptop (WinXP SP2) and a Tivo connecting to it by wireless.

I am assuming that if I switch out the deesktop for a newer model running Vista that the laptop (WinXP SP2) has to be cut out. Or does it?

[The Bar-Abbas Anomaly]

 

Your computers don't care what other devices exist on your network, AdamAntman....  Contrary to the popular commercials, they wouldn't even care if you got a Mac!  The router could, theoretically, but it won't.  Vista won't matter.

[NJAntman]

Sweet!
That opens up some possibilites with my desktop purchase, seems every vendor is pushing Vista hard, one is even offering a Premium upgrade at the same price as XP.

Thanks for that explanation, puts me at ease a bit.

[The Bar-Abbas Anomaly]

 

The vendors are pushing it so hard because Microsoft is pushing them from the other side...  Public enthusiasm just wasn't what they had hoped for or expected.

I personally would wait another year for most of the larger bugs to get ironed out of Vista before I take the plunge.

[E_Look]

Here's a dumb networking question- I have a Netgear firewall router linking a few PCs in a small home network using WEP encryption.  How come my brother cannot join into my network with his Mac laptop... even if I gave him the password?

For that matter, neither can I with a borrowed IBM ThinkPad. 

[Darth Sidious]

Here's a dumb networking question- I have a Netgear firewall router linking a few PCs in a small home network using WEP encryption.  How come my brother cannot join into my network with his Mac laptop... even if I gave him the password?

For that matter, neither can I with a borrowed IBM ThinkPad. 

Any AllowOnly stuff set in the MAC address filter?

[The Bar-Abbas Anomaly]

Here's a dumb networking question- I have a Netgear firewall router linking a few PCs in a small home network using WEP encryption.  How come my brother cannot join into my network with his Mac laptop... even if I gave him the password?

For that matter, neither can I with a borrowed IBM ThinkPad. 

"Shot in the Dark Reply v1.0" - You are trying to connect by specifying WEP encryption and Pre-Shared Key (PSK), when your wireless router uses WEP and 'Open Authentication'...

[E_Look]

Mr. Neal Bar Abbas, you've lost me there.

I thought the router was set up to run with a preshared key 

[The Bar-Abbas Anomaly]

Mr. Neal Bar Abbas, you've lost me there.

I thought the router was set up to run with a preshared key 

I agree that it sounds right, but the default (and correct) wireless configuration is usually 'Open Authentication'.  When you try to connect from the workstation or laptop, if you have the option make sure you specify Open Authentication with WEP rather than PSK-WEP.

[toasty0]

Here's a dumb networking question- I have a Netgear firewall router linking a few PCs in a small home network using WEP encryption.  How come my brother cannot join into my network with his Mac laptop... even if I gave him the password?

For that matter, neither can I with a borrowed IBM ThinkPad. 

Some netgear models have a maximum number of connections setting. Also, you might try turning your netgear wireless router off for 30 seconds then power it back up. This should clear the connection cache and allow new authenticated logons.

[NJAntman]

May want to check the channel selection also, I had a Linksys adapter refuse to connect to a linksys router until I set the router to channel 6.