[139366] in North American Network Operators' Group
Re: IPV6 Training Books
daemon@ATHENA.MIT.EDU (Mark Andrews)
Mon Apr 4 20:59:54 2011
To: Michael Ruiz <mruiz@lstfinancial.com>
From: Mark Andrews <marka@isc.org>
In-reply-to: Your message of "Mon, 04 Apr 2011 19:43:09 GMT."
<690D7D20D2507C44BA8066926B2009890867FA@ES1002.ic-sa.com>
Date: Tue, 05 Apr 2011 10:59:31 +1000
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
In message <690D7D20D2507C44BA8066926B2009890867FA@ES1002.ic-sa.com>, Michael R
uiz writes:
> Hello All,
>
> I am looking for some good reading material to get a better=
> understanding of IPV6. I know how to convert HEX into decimal format. Wh=
> at I am looking for is how to under the CIDR notation and break them out in=
> to subnets. Thank you in advance.
If you think in hex its straight forward to do CIDR in IPv6. There
are only three groupings on a non nibble boundaries. You also
display the entire 128 bits with the least significant bits set to
zero. The :: notation is used to shorten the displayed address.
e.g for a /57, /58 and /59 with leading bits of 2001:23bc:fe8d:b200::/56
you would have.
/57 {0,1,2,3,4,5,6,7} {8,9,a,b,c,d,e,f}
2001:23bc:fe8d:b200::/57
2001:23bc:fe8d:b280::/57
/58 {0,1,2,3} {4,5,6,7} {8,9,a,b} {c,d,e,f}
2001:23bc:fe8d:b200::/58
2001:23bc:fe8d:b240::/58
2001:23bc:fe8d:b280::/58
2001:23bc:fe8d:b2c0::/58
/59 {0,1} {2,3} {4,5} {6,7} {8,9} {a,b} {c,d} {e,f}
2001:23bc:fe8d:b200::/59
2001:23bc:fe8d:b220::/59
2001:23bc:fe8d:b240::/59
2001:23bc:fe8d:b260::/59
2001:23bc:fe8d:b280::/59
2001:23bc:fe8d:b2a0::/59
2001:23bc:fe8d:b2c0::/59
2001:23bc:fe8d:b2e0::/59
Note the last nibble before the :: is 0 and is there so that the
final bits are all zeros. The following all represent the same
cidr block.
2001:23bc:fe8d:b2e0::/59
2001:23bc:fe8d:b2e0:0000:0000:0000:0000/59
2001:23bc:fe8d:b2e0:0:0:0:0/59
Normally you just assign /64 subnets and delegate address blocks
on nibble boundaries to end customers, e.g. /48, /52, /56 or /60.
This means that end customers don't need do deal with cidr block
if they don't want to. They can just route individual /64.
> MAR.
>
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: marka@isc.org
