IPv6 • VERY briefly
The Basics • Next generation IP addressing • Needed because we are running out of IPv4 addresses (primarily) • Expressed as 8 groups of 4 hexadecimal digits • 2001:0db8:85a3:0042:1000:8a2e:0370:7334 • Several benefits can be gained . . .
IPv4 vs IPv6 • IPv4 addresses are 32 bits long • Allows for about 4.29 billion addresses • IPv6 addresses are 128 bits long • Allows 3.8 x 1038 addresses • That’s 380 undecillion (or 48 octillion addresses for each of the 7 billion people on earth)
IPv4 vs IPv6 • There are several other differences (these are a few): • Simplified packet header • Simplified routing • Allows jumbograms (more on this later) • Options extensibility (next slide) • Better mobility
Options Extensibility • The packet header has a fixed length (40 octets) • Extra options can be defined after the header • Limits size to the size of the entire packet • Makes IPv6 extensible without re-design of the basic protocol
Jumbograms • IPv4 limits the size of a datagram to 216 - 1 octets • IPv6 jumbograms can be as large as 232 - 1 octets • Could work better over links that allow higher Maximum Transmission Units
Mobility • Mobile IPv6 avoids some problems with mobile IPv4 • The specifics on this are beyond the scope of this class, but you could look at “Triangular Routing” if you’re curious • Mobile IPv6 is just as efficient as native IPv6
Transition • IPv6 and IPv4 don’t directly “talk” to each other • Transitioning requires a way for what is essentially two independent networks (IPv4 and IPv6) to exchange traffic • This involves implementing translation gateways (Network Address Translation) or tunneling protocols