What is a router, a gateway, and a access point?

Hello, I am new to networking. I have done some research but I have yet to find any definitive answer on what a router, a gateway or an access point really is. What purpose do they serve for a network? IF you know, what purpose and importance do they have for a wireless network. Any help would be greatly appreciated, and an answer rather than a website w/ an answer would be greatly appreciated. Thanks again!

 

Access Point it’s a link from the wireless LAN to the wired network and the Internet beyond. On 802.11 which is set for Wireless.Gateway Typically, computers on a LAN (Local Area Network) won't know the details on how to route messages from subnet to subnet. The gateway should be seen as the point of routing on a network. Mostly on wired networks. Routers selcet which data packets to route between multiple LAN segments. They make intelligent decisions about the path that packets should take around the backbone and they know where the final destination is located. Works on both.
Hope that helps.

 

Yup. Exactly what he said about the wireless access point. Connects a wireless network card to a wired network.

As to the others - also what he said but maybe said simpler for folks who aren't really network aware. This is only directed at TCP/IP although IPX (Novell network protocol) and some others are handled in a similar fashion.

LAN (local area network) is an address and subnet mask combo that puts all the PCs on the same network or subnet (identical meanings in this case). They talk easily among themselves and all traffic is just thru the switch/hub.

But they aren't able to talk to another network. Simply don't know how. That's where the ROUTER comes in. It does know how to move network packets from one network to another (i.e., to route them). In fact, that's about all it does know how to do.

And in your case, you have a network at home and your ISP has another network. Your router simply checks all the packets and when it finds one that isn't from one of your PCs to another, it snags the packet and squirts it out to the ISP. ISP routers & servers take over from there.

GATEWAY address - just the IP address of the router so your PC knows what to do with packets that are addressed to go outside your LAN. The router is acting as your gateway to the real world.

 

Great Job Newt!!

Now explain the OSI model and IP V 6 and you will be cookin with gas!

 

ssmith10pn - just for you.

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IP V6 (that's TCP/IP version 6 as opposed to version 4 that we use now). Short explanation - it's lots bigger. 128bit address vice the 32bit we use now so if you don't want to do the math, 128 bits of addressing gives you 4 billion x 4 billion more addresses than v4.

Or roughly 665x10^21 addresses per square meter of the earth.

IP Address now = xxx.xxx.xxx.xxx
IP Address then = (although they won't stay with this format)
xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx.xxx

So - more than we need right now but with PCs, routers, switches, TVs, phones, refrigerators, cars, etc. all getting to the point where they'll need a unique address or two or 10, it'll be nice to have plenty.

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The OSI Reference Model - how network stuff gets from where it starts to where it is supposed to go in a format that can be understood.

Includes seven layers:

7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data-Link
1. Physical

In people terms it would go something like this:

You are called in by your boss on the 7th floor of your office building. The boss gives you a message that has to get to his wife at home. But the dang thing is heavy and awkward to lug around as is.

You go down to the 6th floor where your companies translators are and give them the message. They translate it into an intermediary language, encrypt and miniaturize it and hand it back.

You proceed to the 5th floor where Security checks the message to be sure it is all there and puts some checkpoints in the message so his wife can be sure she’s gotten the whole message.

Down to the 4th floor where the company efficienty experts analyze the message to see if it can be combined with some other small messages that also need to go to his house. If the message had been even larger and too much for you to handle, they would also have broken it into several smaller pieces so other messengers could take pieces and have it all reassembled into a single message again at the other end. Smaller so you still had room and they would have given you chunks of other messages.

The 3rd floor personnel check the address on the message and determine who it's addressed to and hand you a map of the fastest route.

On the 2nd floor the message is put into a special courier pouch (packet). It contains the message, the sender and destination ID. It would also warn his wife if other pieces were still coming.

Now to the 1st floor where transportation has a fast car waiting for you and you drive to the boss's house.

Once there, the process is reversed. You go from 1st floor upward until you finally reach the 7th with a message in English again and hand his wife, "I'll be late tonight so don't wait dinner ".

 

Newt, that was great
That was an excellent way to make it easier to study.

You left out the anding process of how ip addresses are converted into binary code

 

Shucks ssmith10pn, I don't even know at this point if BriGuy2005 is happy with the router/gateway part.

 

newt,
Ain't that kind of a trick question? I mean, the "OSI layers" is rather broad because of the way Microsoft, Linux, Unix and such use some of the layers of the "7 layered OSI system ". Some of them only use 3 layers. Sorry, heh... Thinking way to much. By the way, awesome explanation.
CCNA, CNA, MCSE, MCP, MCSE+i, N+, A+, FCC.

Has anyone started a thread on Windows 2003 server yet? I am eager to help.

 

OSI LAYERS

here's something I wrote for another thread about the OSI layer model enjoy

There is something called the OSI model. What it does is outline the standards of "networking" protocols and how they operate in the network environment to process packets sent across the network.

There are 7 layers
The Physical Layer which consists of the actual hardware, cables and hubs. Hubs are considered to be in the Physical Layer because the physical layer is considered to be the dumb layer all it does is provide the means of sending packets over a network, no inteligent routing or examination of the packet itself.

The Data Link layer which consists of slightly more inteligent devices. This Data Link layer is broken into two parts, the MAC then the LLC. The MAC(Media Access Control) is what switches operate on(in addition to Bridges, NIC's, and much more), they route and manage the MAC address of nodes on a network and can send the packets ackordingly. Such network configurations consist in the MAC such as the CSMA/CD or Token Ring for example. The next par of this layer is the LLC(Logical Link Control) what this does is provies error control and flow control of the Data Link Layer.

The Network layer is the start of the most known types of networking, TCP/IP is broken into two parts TCP and IP, the IP section of the TCP/IP operates on this layer, the Network Layer. Routers operate on this layer and can route appropriate ip addresses across the network. Everthing I have stated up until this point is considered Connectionless. An example of this is ICMP, when you ping a node, it will operate in this layer. IPX also works in this layer(IPX/SPX).

The Transport layer is the end of the most known types of networking, the TCP section of TCP/IP(Transmission Control Protocol) works in this layer. Such devices are a Gateway for example, and this is the start of the Connection Oriented section of the OSI model. SPX works in this layer as well as NetBIOS and NetBUI.

The Session layer is basically responsible for commiting and ending a session. Such things as an RPC call is where this operates. When you connect to a computer on a network your computer comits and RPC(Remote Procedure Call) which sends authentication information accross the network. NetBIOS also works in this layer along with Lanman

The Presentation layer is what is next, and what this does is prepares the information comited to the protocol encryption to work in the operating systems world. Prepares information to be "read" by the appropriate application.

The Application layer is what is last, the application layer can be considered to be the layer where the applications that work over the network can run. such as FTP, Telnet, DNS and so on.

Each thing on your computer goes from top to bottom Application level to Physical level and when it is received it goes from bottom to top and so on, and this is the transfer of information and how the devices work with the information and where the devices are effective in the network. Hope this is helpful, and lets you know where routers, switches, and hubs operate in the network environment.

Hubs ineffective in an envrionment to manage traffic, they don't know where things are, so they broadcast it to EVERYTHING on the hub.

Switches manage traffice more appropriatly, can manage traffic and keep a list of MAC addresses on each node, and will not broadcast the traffice to everyone. Bridges are not as intelligent but offer a way to stop a bottlekneck in a network.

Routers manage traffic more effectively and offer many different routing protocols. This is the ideal way to go to manage heavy sections of a network, or to offer as a gateway or so on.

Happy Learning, you can find information online and learn more, just search for the OSI model.

 

wakiababa - thanks for the kind words. And a really impressive batch of certs you have. I've sometimes thought I ought to get a few myself. I did MCP on NT3.5 way back when and MCP was the only one they had. But nothing recent.

I sorta like the 7 layer model that zollodav laid out. Every setup I know of uses all 7 ideas but just clump some into a single layer so you appear to have fewer. But they gotta do all the functions or stuff just doesn't work.

We've discussed a 2003 section but decided to wait until questions start showing up. Maybe even a temp rename of 2000 to 2000/3 for a while. I doubt if there will be massive numbers of companies switching right away since there really isn't any major functionality you don't or can't have with 2000. Just prettier lay out. I imagine the NT4 folk will jump right to 2003 but most of them are doing fine with NT4 at this point and probably will for a time. If they do outgrow the domain model and decide to go to AD then in a year or so it would make sense to do it with 2003. But right now that stuff would be a little too cutting edge (or bleeding edge) to run your business on IMO.

 

Well it's all just dependent on what protocol your using, like tcp/ip, it has it's own osi layer model, is just depends. And as far as how linux and unix and windows all talk different languages, that just has todo with the top three layers ussually, how they authenticate, how they use the presentation layer and application layer. 2003, I will not comment on, it's xp, with added junk. lol