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Old 6th May 2013
comet--berkeley comet--berkeley is offline
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Default IPV6 addresses how are they written?

Multiple choice quiz:

A) IPV6 addresses are 4 groups of 4 hexadecimal characters separated by colons.
B) IPV6 addresses are 6 groups of 4 hexadecimal characters separated by colons.
C) IPV6 addresses are 7 groups of 4 hexadecimal characters separated by colons.
D) IPV6 addresses are 8 groups of 4 hexadecimal characters separated by colons.

If you look at the current version of "Absolute OpenBSD" 2nd Edition (PDF), then
page 193 under "IPV6 Basics" says that B) is the correct answer.

If you go to the OpenBSD FAQ section 6.1, it suggests reading the
"Understanding IP Addressing" by 3COM.

http://openbsd.org/faq/faq6.html#Intro

http://www.scribd.com/doc/52483921/3...-IP-Addressing

And if you look on page 43 of the 3COM document you find
"Figure 36: Hexadecimal to Binary Conversion"
which clearly shows that C) is the correct answer.

However if one looks at either the FreeBSD FAQ or the NetBSD FAQ
or Wikipedia then D) is the correct answer.

http://www.freebsd.org/doc/en_US.ISO...work-ipv6.html

http://www.netbsd.org/docs/guide/en/...tml#ipv6-intro

http://en.wikipedia.org/wiki/IPv6
Attached Images
File Type: png hex7-page43.png (25.7 KB, 28 views)

Last edited by comet--berkeley; 6th May 2013 at 11:00 PM. Reason: grammar
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Old 6th May 2013
ocicat ocicat is offline
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Quote:
Originally Posted by comet--berkeley View Post
Multiple choice quiz:

A) IPV6 addresses are 4 groups of 4 hexadecimal characters separated by colons.
B) IPV6 addresses are 6 groups of 4 hexadecimal characters separated by colons.
C) IPV6 addresses are 7 groups of 4 hexadecimal characters separated by colons.
D) IPV6 addresses are 8 groups of 4 hexadecimal characters separated by colons.
According to Wikipedia:

http://en.wikipedia.org/wiki/IPv6_address

The IPV6 address 0:0:0:0:0:0:0:0 can be legitimately abbreviated as ::, so can I guess E) none of the above?

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Old 7th May 2013
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LeFrettchen LeFrettchen is offline
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IPv6 addresses have a size of 128 bits.
So the maximum is 8 groups of 4 hexa, but that's just the limit.


Quote:
Originally Posted by ocicat View Post
The IPV6 address 0:0:0:0:0:0:0:0 can be legitimately abbreviated as ::, so can I guess E) none of the above?
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Old 7th May 2013
comet--berkeley comet--berkeley is offline
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Quote:
Originally Posted by ocicat View Post
According to Wikipedia:

http://en.wikipedia.org/wiki/IPv6_address

The IPV6 address 0:0:0:0:0:0:0:0 can be legitimately abbreviated as ::, so can I guess E) none of the above?

Yes and the IPV6 address 0000:0000:0000:0000:0000:0000:0000:0000 can be legitimately abbreviated as 0:0:0:0:0:0:0:0

so case D) still holds.


Last edited by comet--berkeley; 7th May 2013 at 06:09 AM. Reason: color
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Old 7th May 2013
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Greetings to All,

And the RFCs have it! RFC 2373 states:

RFC 2373 IPv6 Addressing Architecture July 1998


FEDC:BA98:7654:3210:FEDC:BA98:7654:3210

1080:0:0:0:8:800:200C:417A

So the answer is D and the Absolute BSD is wrong!
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Old 7th May 2013
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C'mon guys, do the math. 4 hexidecimal = 16 bits. We all agree that ipv6 addresses are 128 bits in length, so 128/16 = 8.

I don't know if these are typos, but I suspect so, as the hex7-page43 image linked by the OP shows 112 bits, not 128.

Seems more an editing fail than an RFC fail.
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