IP address

[zeeke]

Hi,

Is the IP address unique while on the net?

In receiving mails, the "X-Originator" or "Receive From" field in the Message Header displays an IP address. Does this mean that the IP displayed is the IP assigned to that specific computer???

Dial up access :
1. the ISP assigns a specific IP address to u, right?
2. if u are in a network, (using a Dial Up) will ur IP be the same as the IPs of other computers in the network?
3. if in a network using a proxy server, is the IP address the same for all users?
---- or IP are different for ALL computers on the network using ONE (1) dial up?

I just need to confirm how IP in the network works, this is in conjuction with the IPs shown in email headers.

Thanks so much, any info is greatly appreciated!

 

[FaiTHLeSS]

1. the ISP assigns a specific IP address to u, right?

Yes

An IP is unique ie. no two people can have the same IP while connected to the internet or a LAN. If they did it would cause conflicts or data wouldn't get routed to 1 of the computers.

2. if u are in a network, (using a Dial Up) will ur IP be the same as the IPs of other computers in the network?

Not sure what you mean here 2 computers cant have the same IP address. There will be a range of IP's used on networks. There is different classes of IP range ie Class A Class B Class C are the main 3 each different class being able to have more hosts.

3. if in a network using a proxy server, is the IP address the same for all users?
---- or IP are different for ALL computers on the network using ONE (1) dial up?

Really depends on how the network has been setup, If your using dailup then its most likely its a NAT setup so yes to the external world would see you all as haveing the same IP.

 

[zeeke]

Thanks,

The thing is, I received two emails, from two different users, using different computers located in one office.
Their resulting IP is the same.
What does this tell?
Are they using a proxy server having a dial up connection? How come they have the same originating IP?

 

[FaiTHLeSS]

Its hard to tell would really need to know the setup of the network to be able to tell. It could be that they are using a NAT setup. But from the details you have given it sounds like it is a NAT setup this is where the LAN will use a private range of IP's and they will have a server or router doing NAT( Network Address Translation) all the computers on that network wanting to communicate with the outside world will go through this device this resulting in them having the same external IP address.

 

[zeeke]

thanks again faithless, i wud just like to confirm what i know about IP addressing in the internet.
thanks bout the information on NAT.
as what ive been told, they are using a dial up and possibly using a proxy server in their network.
thanks again FaiTHLeSS !!!

 

[zeeke]

Just in case u wud have any idea on what the IP on this message header means:


X-Message-Info: JGTYoYF78jH4nxnJkpdTX9QvpyeCmd1A
Received: from web41404.mail.yahoo.com ([54.124.44.3]) by mc12-f3.hotmail.com with Microsoft SMTPSVC(5.0.2195.5600);
Fri, 17 Oct 2003 03:06:36 -0700
Message-ID: <20031017100631.80296.qmail@web41404.mail.yahoo.com>
Received: from [211.21.161.2] by web41404.mail.yahoo.com via HTTP; Fri, 17 Oct 2003 03:06:31 PDT
Date: Fri, 17 Oct 2003 03:06:31 -0700 (PDT)




PS
I have changed only the IP numbers on this data, IPs are not real the others are.

 

[FaiTHLeSS]

211.21.161.2 is the IP of the client sending the mail

54.124.44.3 is the IP of 1 of yahoo's mail servers