nanog mailing list archives
Re: IPV6 Training Books
From: Mark Andrews <marka () isc org>
Date: Tue, 05 Apr 2011 10:59:31 +1000
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
Current thread:
- IPV6 Training Books Michael Ruiz (Apr 04)
- Re: IPV6 Training Books Niclas Zeising (Apr 04)
- RE: IPV6 Training Books Stefan Fouant (Apr 04)
- RE: IPV6 Training Books Michael Ruiz (Apr 04)
- Re: IPV6 Training Books Mark Andrews (Apr 04)
- Re: IPV6 Training Books Roman (Apr 04)
- Re: IPV6 Training Books Owen DeLong (Apr 04)
- Re: IPV6 Training _links_ Vesna Manojlovic (Apr 05)
- Re: IPV6 Training _links_ Justin Wilson (Apr 05)
- Re: IPV6 Training _links_ Mike Oliver (Apr 06)