Networking Question

Dave

Joined Nov 17, 2003
6,970
By definition a network address is an address that serves as a unique identifier for a computer on a network.

So isn't the answer to the question that an IP address is a specific example (the most common example) of a Network Address. Network Addresses encompasses other addressing modes such as MAC addresses etc.

Dave
 

studiot

Joined Nov 9, 2007
4,998
By definition a network address is an address that serves as a unique identifier for a computer on a network.

So isn't the answer to the question that an IP address is a specific example (the most common example) of a Network Address.
Yes well put I agree.

Network Addresses encompasses other addressing modes such as MAC addresses etc.
Not quite so well put as MAC addresses are security devices, not network addresses.

A Network Address not only facilitates device identification, it also allows traffic to be directed to a specific destination (that's its purpose). Allocation of network addresses is under the control of some (central ) controller and not allocated by the devices themselves. A MAC is specific to a device.
In fact the devices at a given Network Address may change, without changing the NA.

Another example of a network address is www.allaboutcircuits.com. The HTTP:// bit is not an address it specifies the code used.
 

AlexR

Joined Jan 16, 2008
732
More specifically the network address is the part of the IP address that the router uses when making a decision of what to do with the IP packet.
When you set up an IP address you specify what part of the address constitutes the network part and what part is the host part by means of the network mask. Routers only make routing decisions based on the network part of the IP address.
 
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triggernum5

Joined May 4, 2008
216
In the context that the OP asked, the network & IP addresses are the same thing.. More technically, an IP adress can be broken down bitwise in comparison to the subnet mask to determine the network, and host portions of the address.. Any bit set to 1 in the subnet mask means that same bit in the IP address represents the network.. 0's represent the host..
The simplest case with subnet 255.255.255.0 and say IP 192.168.1.10 means that 192.168.1 is the network portion, and 10 is the host (or machine) portion.. You need a gateway (router fo instance) between your host portion and other networks to communicate..
I'm not trying to school those in this thread who know this, I'm just outlining it..
 

studiot

Joined Nov 9, 2007
4,998
What is the difference between an IP address and a Network address?
I think the OP asked a very reasonable question.

Of course the term 'network' is a very general and perhaps a bit vague term that we apply to lots of different situations.

The term IP is quite specific and only applies to one type of network and even then only one option in common use, although it is gradually taking over as the option of choice.

We should explain why for instance cards plugged into a PC motherboard do not constitute a network in the generally accepted sense. Many respond to specific addresses, set by DIP switches.
 

AlexR

Joined Jan 16, 2008
732
All you folks who think that IP addresses are the only form of network addressing should re-read Daves post.
I have just re-read Dave's post as suggested and I'm afraid that much of what he says is wrong.
By definition a network address is an address that serves as a unique identifier for a computer on a network.
So far so good.
So isn't the answer to the question that an IP address is a specific example (the most common example) of a Network Address. Network Addresses encompasses other addressing modes such as MAC addresses etc.
The term "Network Address" has a very specific meaning in the IP world and a single IP address is not an example of a network address. A single IP address can be part of a network but a single IP address can not be a network address.

The network address specifies a range of IP addresses that belong to one network. It is common to specify the network address by stating the base IP address and a network mask which tells you what range of addresses the network covers.

If we are talking about IP networks (as I believe the OP was) them any addressing mode other than IP is irrelevant. The MAC layer has no concept of networking so there is no such beast as a MAC network address. There is a MAC broadcast address but that is a different kettle of fish again (more like a red herring).
 

triggernum5

Joined May 4, 2008
216
I think the pedantic points have been outlined, but in the IP world, MAC addresses are the rudimentary network addresses.. As far as routers are concerned IP addresses are just aliases assigned to MACs.. The router doesn't think to itself "192.168.1.10 is attached to cable port 3, so I'll send data down that cable".. It says "192.168.1.10 is assigned to this MAC address, so I will send data to that MAC.."
 

bertus

Joined Apr 5, 2008
20,465
Hello,

Here is a description for a Network adress :

Network Address:
These protocols handle the way machines are addressed, both by a unique number and a more common symbolic name.
• ARP (Address Resolution Protocol): Determines the unique numeric addresses of the machine on the network.
• DNS (Domain Name System): Determines numeric addresses from machine names.
• RARP (Reverse Address Resolution Protocol): Determines addresses of machines on the network, but in a manner backward from ARP.

And here for IP address classes:


IP Address Classes:
An IP address contains a network part and a host part, but the format of these parts in not the same in every IP address.



Figure 87 shows the IP address classes.​
Not all network addresses or host addresses are available for use. The class A addresses, 0 and 127, that are reserved for special use. Network 0 designates the default route (is used to simplify the routing information that IP must handle) and network 127 is the loopback address (simplifies network applications by allowing the local host to be addressed in the same manner as a remote host). We use the special network addresses when configuring a host.
There are also some host addresses reserved for special use. In all network classes, host number 0 and 255 are reserved. An IP address with all host bits set to zero identifies the network itself. Addresses in this form are used in routing table listings to refer to entire networks. An IP address with all bits set to one is a broadcast address (is used to simultaneously address every host on a network). A datagram sent to this address is delivered to every individual host on that network.
IP uses the network portion of the address to route the datagram between networks. The full address, including the host information, is used to make final delivery when the datagram reaches the destination network.



Figure 88 shows host communication on a local network.







This comes from the following page:​
http://www.citap.com/documents/tcp-ip/tcpip001.htm

Greetings,
Bertus
 

studiot

Joined Nov 9, 2007
4,998
I suspect the OP is long gone from this thread, but he did ask for the difference between a network address and an IP address.

Anyone who has ever made a printer, that does not use IP addressing, available on a network (i.e.e most older types) will know that there is a difference. And what's more no amount of IP addressing will ever allow another network user to print on one of these printers.

Yet it can be done. For my sins I have several such ancient behemoths to look after.

Another more modern example would be setting up a video conferencing link, over IP. If you have ever done this you will know that there is much more than just the Ip addressing to set up to make it work.

So I repeat: in today's modern networking world, not all networks use IP addressing.

The question of MAC 'addressing' I agree is not a true network addressing mode. I have already dealt with this in an earlier post. If you replace machine A (MAC XXXXXX) with machine B (MAC YYYYYY) at a given IP, the system will work as before. The packets are now sent to the same IP, but a different MAC. This is, of course how IP leasing works!

Nobody answered my question about a pc card in a motherboard.
 

triggernum5

Joined May 4, 2008
216
Now the debate is shifting to what defines a network if legacy/internal addressing schemes are included..
Phone numbers are another form I suppose..
 

studiot

Joined Nov 9, 2007
4,998
Which would be why it is called the

Public Service Telephone Network (PSTN)?

or is it a

Packet Switched Telephone Network

Yes the definition of Network is wide and wooly with lots of grey areas. there are an infinite number of possibilities.

on the other hand

IP address are precisely defined and there are only a finite number of them
 
I keep reading all the posts in this thread but all I read are people "dancing around the question". Throwing out info on random things.
Which would be why it is called the

Public Service Telephone Network (PSTN)?

or is it a

Packet Switched Telephone Network

Yes the definition of Network is wide and wooly with lots of grey areas. there are an infinite number of possibilities.

on the other hand

IP address are precisely defined and there are only a finite number of them

Nanobyte he is the answer to the question you asked.
What is the difference between an IP address and a Network address?
What I think your looking for is what is the difference from a IP that a router gives to local computers (Network address) and a Public IP address.

The difference is that the router is told to give out a certain range of non-route able IPs example: 192.168.1.100 or 192.168.0.100. Which the helps the router to find out who requested what. Story time! Say I wanted to go to http://www.allaboutcircuits.com . Ok so I type the URL into my browser and then that request is sent to the router to send to out to the "Internet". Then when the sent is complet http://www.allaboutcircuits.com sends a request to my "Public IP address" and that then comes to the router and says, "Who asked for this request?". Then your computer says, "I did!" So thats why we use "Network address". Mostly used for internal networking.

Now on to "Public IP address". (Which is what I think your refuring to when you says IP address.) The Public IP address is what the world sees as the requst being sent out. Like when you sent that request to get the website. The webhost saw our Public IP address and then sent the request back to that IP. Which is your modem. Who sends it to the router to see who asked for that website.
 
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