primary ip address

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May 31st, 2005, 06:13 AM
littlenick

primary ip address

i was solving exercises of TCP/IP stevens and encoutered this question
..........................................

If you have an account on a host that is connected to a TCP/IP internet, what is its primary IP address? Is the host connected to the worldwide Internet? Is it multihomed?

............................................

an Internet is same as internet but reverse is not true.but as far primary ip address is concerned i have got no idea.I have my written examiation tomorrow and this question was asked last year.

I tried searcing the web but can't find the answer
May 31st, 2005, 07:36 AM
dmorgan

I think you are confusing the words, here. Internet (which is TCP/IP stack based) is what we all use to connect to a totally remote website (like antionline.com - which is hosted in Connecticut if whois.sc is correct) or a service (like ssh, ftp, or POP/SMTP mail server) a intranet (which can be NetBUEI or IPX/SPX or a thousand other protocals based) is what we use to connect to a service on the company's network. This service (sometimes your company's daily web page or ftp of ssh or one of a hundred things) may or may not be connected to the internet, and is on your local network. The internet is not. It is beyond you company's routers or gateways or whatever.

Sorry if I am going over redundant information. I am a little drunk. :D
May 31st, 2005, 07:42 AM
Striek

The question is simply too vague. Almost any answer is correct.

Quote:

If you have an account on a host that is connected to a TCP/IP internet, what is its primary IP address?

Well that could be absolutely any address. You cannot determine a host's IP address given only the fact that it is on an internet. This would be akin to asking "If you live in a house that is on an interstate freeway, what is your address?"

Quote:

Is it multihomed?

Well maybe it is and maybe it isn't. Again, an internet connection alone is not enough information to answer this question. It does not negate the possibility of another internet connection, nor the possibility of a intranet connection on the other side. But maybe it is single homed, if it has only one connection. This would be akin to asking "There is a path in front of your house. Is there a path in the back as well?"

So unless there is some other information regarding these questions, there is simply insufficient information to answer them defintively.

For reference, officially, the Internet (capital I) referes to the worldwide Internet. An internet (lower case I) refers to any collection of more than one intranet. An intranet is a network with clearly defined logical borders, unlike an internet. Kind of like regional roads being an intranet and interstates being an internet. If we were to adopt a standard naming convention for all the roads in the world, this would be the Internet. Quite likely you know that already, but one can't be too sure.
May 31st, 2005, 08:23 AM
HTRegz

Hey Hey,

The question is very vague,

I'm wondering if it's looking for the very basic answer of an RFC 1918 Address... a poorly worded question to see if you know the RFC that pertains to private addressing. They use the word Internet repeatedly... and the RFC is actually entitled 'Address Allocation for Private Internets'

Anyways.. that's my take on it.

Peace,
HT
May 31st, 2005, 09:27 AM
Striek

<begin shameless ego boost>

Yes but that's a title, and according to the rules of english grammar, all verbs, subjects, and nouns should be capitalized, but not prepositions. An internet is a noun, and is therefore capitalized due to its status as a noun in a title and not its place in the world.

</end shameless ego boost>

Dad raised me to be a spelling, punctuation, and grammar nazi, with daily lectures on the idioms of English.

Sorry
May 31st, 2005, 10:11 AM
cybersamurai

Quote:

You cannot determine a host's IP address given only the fact that it is on an internet

i beg to differ there...striek. sorry to say but some of you are answering there own questions, instead of asking him to aticulate the question! coz frankly we can't tell what he's askin
May 31st, 2005, 10:49 AM
Tiger Shark

I agree that he misread the first "internet". It probably read intranet but the tired student is gett cross eyed.... ;)

The host's primary IP address on an intranet would be private. It would often be further connected to the Internet via some form of NAT or proxy device. It may be multihomed for it's internet connection should it not be using a NAT or proxy device. The previous could all be true but much would also depend upon the rights granted to the account referred to in the question.

That's the answer I would give and say "to hell with it" because the question is possibly the worst question I have ever seen in any test, (barring, of course, the philosophy question that asked "Is this a question?").
May 31st, 2005, 02:45 PM
jdenny

Striek,

Quote:

Dad raised me to be a spelling, punctuation, and grammar nazi, with daily lectures on the idioms of English.

Must be hard hanging on a site where most members think that l33t sp33k is cool... :)

Quote:

Sorry

Missing a period, I guess? :cool:

Peace always,
<jdenny>
May 31st, 2005, 05:05 PM
littlenick

Quote:

Originally posted here by Tiger Shark
I agree that he misread the first "internet". It probably read intranet but the tired student is gett cross eyed.... ;)

I am sure it was internet here is a link to a online version of that book look at exercise of chapter 1 ....question number 5

http://angrypacket.com/~enz00/txts/tcpip.pdf

anyway i am really tired now will go to bad but before that i had one more question a data of size 8193 bytes has to be transmitted on ethernet we have to find number of fragments required.

thanks all for this wonderful discussion.
see ya.
May 31st, 2005, 05:21 PM
zENGER

Wow, that book was written in 1993!

None the less my answers to the questions would ahve to be

The one you specify as the default
It can be on the Internet
It can be multihomed

They seem to give you a lack of information to really answer that question.
May 31st, 2005, 06:21 PM
Tiger Shark

I'd love to see the examiner's answer to that question..... because it's retarded if that really is the wording..... No, I'm not looking through 432 pages to find it.... ;)
May 31st, 2005, 07:39 PM
HTRegz

Hey Hey,

First off... let me just say who decided that Internet and internet would mean different things and why in 6+ years of school with IT related courses have I never heard of this before? Is this something that the occasional egghead pulls outta their ass or am I just oblivious?

Anyways... Let's exame what we're given to work with for this book

Quote:

Multihomed
A router, by definition, has two or more network interface layers (since it connects two or more networks).
Any system with multiple interfaces is called multihomed. A host can also be multihomed but unless it
specifically forwards packets from one interface to another, it is not called a router. Also, routers need not be
special hardware boxes that only move packets around an internet. Most TCP/IP implementations allow a
multihomed host to act as a router also, but the host needs to be specifically configured for this to happen. In
this case we can call the system either a host (when an application such as FTP or Telnet is being used) or a
router (when it's forwarding packets from one network to another). We'll use whichever term makes sense
given the context.

Quote:

Internet Addresses
Every interface on an internet must have a unique Internet address (also called an IP address). These
addresses are 32-bit numbers. Instead of using a flat address space such as 1, 2, 3, and so on, there is a
structure to Internet addresses.
These 32-bit addresses are normally written as four decimal numbers, one for each byte of the address. This
is called dotted-decimal notation. For example, the class B address of the author's primary system is
140.252.13.33.
The easiest way to differentiate between the different classes of addresses is to look at the first number of a
dotted-decimal address.

It is worth reiterating that a multihomed host will have multiple IP addresses: one per interface.
Since every interface on an internet must have a unique IP address, there must be one central authority for
allocating these addresses for networks connected to the worldwide Internet. That authority is the Internet
Network Information Center, called the InterNIC. The InterNIC assigns only network IDs. The assignment
of host IDs is up to the system administrator.

There are three types of IP addresses: unicast (destined for a single host), broadcast (destined for all hosts on
a given network), and multicast (destined for a set of hosts that belong to a multicast group).

Quote:

The Internet
In Figure 1.3 we showed an internet composed of two networks - an Ethernet and a token ring. In Sections
1.4 and 1.9 we talked about the worldwide Internet and the need to allocate IP addresses centrally (the
InterNIC) and the well-known port numbers (the IANA). The word internet means different things
depending on whether it's capitalized or not.
The lowercase internet means multiple networks connected together, using a common protocol suite. The
uppercase Internet refers to the collection of hosts (over one million) around the world that can communicate
with each other using TCP/IP. While the Internet is an internet, the reverse is not true.

Quote:

The Question
1.5 If you have an account on a host that is connected to a TCP/IP internet, what is its primary IP address? Is
the host connected to the worldwide Internet? Is it multihomed?

The author has actually published several books.. and I'm not sure how.. I think he's on crack.. I've even checked the Errata (typo's and corrections) which goes up to a 14th edition (1998) and there's no fix for this problem..

I would have still stuck with the fact that it want's something to do with RFC 1918 addressing, except that in the entire introduction (and also in his 3rd chapter on IP) there's no mention of Private addresses... he's even got an RFC section in the introduction.. and it's not mentioned..

Answer:
Primary IP Address: a unique unicast address?? That's about as close as you could get to answering this question
Is it on the Internet: Possibly
Is it multihomed: If it's on the Internet and routing between the Internet and internet..

I wouldn't even give this book to my lil sister as an intro to computers.. It's completely bogus... The tutorials on AO comprise a better networking book than this POS.

Peace,
HT