Its ever so interesting to listen/eavesdropping in to conversations between ICT equipments, as they go through trying to determine who are the visitors and the mechanism of identification.Some examples maybe as follows:-
Browser Client talking to a webserver
Client > Hello, webserver
Webserver > Hello client, what is your IP address?
Client > Here is my IP, Gimme webpage (get index.htm)
Webserver > Hey Mr DNS, what is this guys name, this guy having this IP address?
DNS > Here, his name is something.domain.com (if the name is listed by sysadmin in reverse lookup)
Webserver > Ahhh, Mr Client, ok, I am going to let him access the page, here's the webpage, let me put him into my log.
Mail server receiving mails and checking for SPAM,
Client1 > Hey Mail server, I am going to send this mail to U.
Mail server > Roger, but before I receive the mail U are sending, I need to check with my friend, Mr RBL (Block List).
Mail Server > Hey Mr RBL, this mail client 1 is going to send me mail, do you think the domain is legit?
RBL server > My man Mail, hey this guy's domain ain't legit, if you receive any mail, just throw them out.
Mail server > Yo , mail client 1, you aint legit, i am going to ditch U.
Client 2 > What about me , mail server ? Can I send U mail destined to one of your users.
Mail Server > Hey Mr RBL, this mail client 2 is going to send me mail, do you think the domain is legit?
RBL server > My man Mail, hey this guy's domain is legit, you can receive any of his mail.
Mail Server > Thanks Mr RBL, Yo...Mail Client 2, yup...you're legit, send me the mail!!
Mail Client 2 > Here is my mail, please deliver to receipient please.
Mail Server > Roger , but you know I need to check it with the colleague here Miss SPAMAssassin.
Mail Server > Darling, Miss SPAMassasin, can you be a dear and check whether this is SPAM?
Miss SPAMassassin > Darrrling, hand it over and let me go through...
Mail Server > Here you are, bunch of mail from Mail Client 2...
Miss SPAMassassin > Hmmmm....looks like bunch or Sales Material to many people and its got this thing in header called VIAGRA. Looks like SPAM to me. I am going to tag this as SPAM. Hey Mr Mail Server, what do I do with this SPAM?
Mail Server > Ohhhh...I have a folder for that, possible SPAM, pass it to me then.
Miss SPAMassassin > Here you are luv, thanks for processing it. Can u tell the receipient, the mails are possible spam.
Mail Server > Yeah, I'll tag them and put it possible SPAM folder. I hope the recepient is told that they can review the tagged mail in possible SPAM folder. Some Service providers don't tell their users ;-) these small things
Now, isn't that IT imitating LIFE. Takes a lot to create a trust relationship, even in the IT world. I wonder what will be the conversations during a SSL session? Maybe I shud learn from IT rather then learning about IT so that I do not face too much casualties ;-)