1.8 IPv6 Addressing

128

• IPv4 has 32-bit length addresses

• IPv6 has ___-bit length addresses

  • Split up into 8 segments of 16 bits each

Compression rules

• Groups of zeroes (0000) can be abbreviated with ::

• Leading zeros are optional, can be removed

  • Zeros that come before a non-zero number

  • Ex. 0001 becomes 1

2600:DDDD:1111:1::1

2600:DDDD:1111:0001:0000:0000:0000:0001 compressed

2601:4C3:4002:BE00::66

2601:04C3:4002:BE00:0000:0000:0000:0066 compressed

6to4 addressing

• Method of tunneling IPv6

• An IPv6 packet is sent over IPv4, by encapsulating IPv6 within IPv4

• Requires a special relay router; troublesome

• Not used anymore

4in6 tunneling

• Method of tunneling IPv6

• Transfer IPv4 traffic over an IPv6 network, by encapsulating IPv4 within IPv6

• Not used anymore

Dual-stack routing

• IPv4 and IPv6 are being used at the same time

• Most devices now will probably be using this

• Apps can decide to use IPv4 or IPv6

NAT64

• Translate IPv4 address to IPv6

• Requires a NAT64-capable router and DNS64 server

• NAT is usually used to translate private IPv4 to public IPv6

NAT64 process

1. Client (IPv6) makes request to DNS64 server

2. DNS64 server makes request to destination DNS server (IPv4)

3. DNS server sends back IPv4 address to DNS64 server

4. DNS64 server sends IPv6 version of the IPv4 address to the client, which is the address to the NAT64 router

5. Now, when the client wants to comm with the IPv4 network, it will send a SYN to the NAT64 router

6. The NAT64 router will translate the IPv6 address to a IPv4 address, and then send the comm to the IPv4 network