Hello tellme555,
This is a very good question! I believe it best to answer all of your
questions in one section, as they all have the same answer :-) I can
tell you have a good understanding of the internet, but for sake of
thoroughness, I am explaining everything as if you needed it.
Q. What does the 66 number from yahoo mean?
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This number is called an I.P. address. It stands for internet
protocol, and every active website in the world has a number like this
associated with it's name. The internet works on numbers, and not the
names we commonly refer to. What you see as Yahoo.com is seen as
something like 66.218.93.xxx to other computers and networks.
Here is what Yahoo looks like sometimes, to a computer in IP format :
66.218.71.63
Here is link to a technical definiton of an 'IP address':
http://www.webopedia.com/TERM/I/IP_address.html
Here a small walkthrough of how this works :
- A user like yourself types in Yahoo.com.
- The internet sees the request and maps the request to a number.
- The number is requested at Yahoo.
- The Yahoo site responds by displaying it's webpage.
Sure there is a much more detailed explanation for this process, but I
am not here to confuse, rather to help. If you visit the link above,
you will be able to read further as to what the '66' means with
regards to the size of network that the sending server (computer)
resides in.
I did a 'name server' lookup, to show you where these numbers point
to. They do in fact, all point to a Yahoo entity:
domain name pointer UNKNOWN-216-136-224-255.yahoo.com (a 216 lookup)
domain name pointer UNKNOWN-66-218-93-255.yahoo.com (a 66 lookup)
In the future, you can check the credibilty of these numbers by using
what is called an nslookup tool. (Name Server lookup) I use this one :
nslookup at the University of Antwerp
http://cc-www.uia.ac.be/ds/nslookup.html
Q. How does this relate to the emails that I have been getting?
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Email systems derive from computers too! These computers are assigned
IP addresses as well. When they send out email, it is an automatic
function to include a 'header' that contains all the information that
you have outlined. The 'helo' statement you see is part of the
standard language that email systems use to communicate with each
other.
The '4' that you are referring to is simply a part of the IP address
of the originating email server. Yahoo can 'alias' different domains
(web) to allow them to use the same 'web' to deliver email, and at the
same time effectively manage the load of such a daunting task.
This number will, and should change frequently as Yahoo.com has
millions of email users. This requires them to balance all the
handling of sending and receiving emails with a network of different
computers. Everytime you get an email, it could be from a different
server, thus the different number.
Yahoo will not explicitly change the sending address for one user.
This is simply a function of the overall process. Their network is
responsible for sending millions of messages, so they utilize programs
to ensure that your message is indeed sent, even if a sending server
with an IP you normally may see is not working or was removed from the
network.
As you have already noted, they serve their advertising from different
servers. This is just probably a function of the way they choose to do
this. They can certainly use the 216.136.224. if they choose to. This
just seems to be a business choice to seperate cetain funtions within
their network. There could many other reasons, but without ever being
inside Yahoo, this is just a guess. As I noted earlier, you will see
that the first numbers have to do with the size of the network. The 66
falls under a Class A Network. You can see the different
specifications here for easy reference:
Class A - supports 16 million hosts on each of 127 networks
http://www.webopedia.com/TERM/I/IP_address.html
Most of my answer comes from first hand knowledge and working
experience. To assist with certain parts of this answer I searched
Google for:
IP address
://www.google.com/search?q=IP+address
I hope this answers your question. Should you need further
clarification, please ask before rating this answer, as I would love
to be of further assistance.
Thanks for the question tellme555!
SgtCory |
Clarification of Answer by
sgtcory-ga
on
26 Nov 2002 11:01 PST
Hello tellme,
I don't mind at all :-)
Q. When a sender uses Yahoo to email, can they (sender) too change
their
(personal ISP) IP? or will yahoo capture the real IP of the sender.
A seasoned hacker could indeed spoof the IP address. He would have to
go to great lengths to do this, but it can be done. Here's the
technical definition of 'IP Spoofing':
"technique used to gain unauthorized access to computers, whereby the
intruder sends messages to a computer with an IP address indicating
that the message is coming from a trusted host...."
http://www.webopedia.com/TERM/I/IP_spoofing.html
The hacker finds a valid host, (such as yours or mine) and modifies
his message headers to display different binary information and data
that would be passed to Yahoo as valid.
This is always a concern of sites like Yahoo, and I must admit, they
do stay on top of most of their security issues. If you suspect foul
play, you should contact them - I'm sure they would love to hear from
you.
Hope that clears this up for you a little!
Thanks again -
SgtCory
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