IPv6

1. Network layers and IP
2. Routing and subnets
3. Problems with IPv4
4. Solutions of IPv6
5. SLAAC
6. IPv4 in IPv6

Under:
Link-layer, MAC (Ethernet, Wi-Fi)
Intra-network communication

Upper:
Transport-layer, TCP / UDP
Data communication

Middle:
Internet layer, IPv4/6
Inter-network communication

2. Routing and subnets

CIDR notation:
192.168.0.0/24 - 192.168.0.XX

2a0d:d9c0:1234:abcd:5678:cdef:1234:4567/64
2a0d:d9c0:1234:abcd:xxxx:xxxx:xxxx:xxxx

192.168.0.0/24 to 192.168.1.0/24
2a0d:d9c0::/64 to 2a0d:d9c1::/64

3. Problems with IPv4

Not enough (public) addresses!

Private subnets allow extension through NAT

192.168.0.0/16 behind 45.134.135.1

Problems: state, complexity...
And *still* not enough addresses!

4. Solutions of IPv6

Many, many, *many* more addresses
Every device has an address, no NAT
Enough for everyone.

(security: NAT does not provide security.
Proper firewalling does.)

Otherwise, nothing basic really changes
Devices have an IPv6, talk to others over link-layer
Same difference!

5. SLAAC
StateLess Address AutoConfiguration

Usually, in IPv4, DHCP
Requires manual configuration

In IPv6, equivalent is SLAAC
* MAC addresses to autoconfigure address in a subnet
* Device Address Duplication built-in checks
* More work for the routers

Router Advertisements, Router Solicitation
Neighbor Advertisements, Neighbor Solicitation

2a0d:d9c0:1234:5678::/64 + MAC address =>
2a0d:d9c0:1234:5678:224:81ff:fe7d:da46

6. IPv4 in IPv6

Same technique as SLAAC: encode IPv4 in IPv6 /64
2a0d:d9c0:1234:5678:192.168.42.42

We can use a translation service to provide IPv4 connectivity to IPv6 hosts.
NAT-like: IPv6 can initiate to IPv4, not the other way around.