More ideally, you give every end site a /48 if they want more than one network.
Owen On Apr 4, 2011, at 5:59 PM, Mark Andrews wrote: > > In message <[email protected]>, 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: [email protected]
