Getting Started with IPv6
Sean Collins

About the Presenter
Sean Collins
Core IT Pro
www.coreitpro.com
sean@coreitpro.com
https://github.com/sc68cal

Quick Refresher on IPv4
RFC 791
Released September of 1981, when I was -6
Classful Network Architecture
ARPANET

IPV4 THEORY
32 Bit addresses (2^32, or ~4.3 Million possible addresses)
Split into two pieces
Network identifier
Host identifier

IPv4 Classes
A class
First 8 bits of the 32 bits designated the network
B class
16 bits designated the network
C class
24 bits designated the network

CIDR
Classful networking was too rigid
A class A network allows ~16 million hosts (2^24)
A class B network allows ~65,000 hosts (2^16)
A class C network allows 255 hosts (2^8)

CIDR
Allowed the network to be split into smaller pieces
Have a network identifier use 20 bits, giving you 12 bits for hosts (2^12
or 4095 hosts)
If that’s not enough hosts, use 19 bits for a network identifier, and now
you have 8191 (2^13)
Much more flexible than the old scheme.

Trouble Is.....
CIDR notation made routing tables BALOON in size
Oh, and we’re also running out of addresses.
IPads and iPhones and Droids
IP enabled Pants
etc...
NAT

IPv6
128 Bit addressing
2^128 possible addresses
5x10^26 addresses for each human being on earth

This is Big (tm)
No more CIDR
No more NAT

IPv6 Theory
Just like IPv4, two parts to an address
Network Identifier (called a Prefix in IPv6-speak)
Host Identifier

Network Identifier
Nothing really different
Just larger allocations
Dirty little secret:
They didn’t pick 128 bits just to never run out
It made routing much easier, since you can give huge chunks of
addresses to one network operator, rather than having /16’s all over the
place

Host Identifier (This is Cool)
Generated from your MAC Address
Yep. You need to buy a Mac.
Just kidding
MAC addresses are unique identifiers for each network card
IPv6 combines the prefix (network identifier), with the MAC address to
create an IPv6 address.

MAC Address
IPv6 Address

Bootstrap Yourself Into IPv6
Using FreeBSD
Install FreeBSD
Good documentation
Solid base install (DNS, Mail, etc..)
Get yourself an IPv6 address
No native IPv6? Use a Tunnel Broker
http://www.sixxs.net/

Configure IPv6
FreeBSD Handbook: Ch. 31 - Advanced Networking
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/
network-ipv6.html

Deploy IPv6 Addresses To Hosts On
Your Network
Three Ways
DHCPv6
Stateless Auto-configuration
Static

Setting up IPv6 for clients
If you are using a Tunnel Broker, you will need to apply for a subnet
FreeBSD Box -> 2001:4830:1600:33b::2
Subnet -> 2001:4830:1601::/48
Laptop -> 2001:4830:1601::fa1e:dfff:fed9:16f9
Cellphone -> 2001:4830:1601:0:a6ed:4eff:fe69:cedb

DHCPv6
Dynamic Host Configuration Protocol
New version, supports IPv6
Useful for networks that already rely on DHCP
A good migration strategy

Stateless Auto-configuration
FreeBSD server runs rtadvd(8)
http://www.freebsd.org/cgi/man.cgi?query=rtadvd&sektion=8
Clients run rtsol(8)
http://www.freebsd.org/cgi/man.cgi?query=rtsol&sektion=8

rtadvd(8) Configuration

Downsides to Auto-Configuration
rtsol(8) and rtadvd(8) currently have experimental support for sending info
about DNS
CFT: IPv6 DNS autoconfiguration (RFC6106 RDNSS and DNSSL)
http://www.mail-archive.com/freebsd-net@freebsd.org/msg36212.html

World IPv6 Day!
http://isoc.org/wp/worldipv6day/
“On 8 June, 2011, Google, Facebook, Yahoo!, Akamai and Limelight Networks will be amongst some of the major
organisations that will offer their content over IPv6 for a 24-hour “test flight”. The goal of the Test Flight Day is to
motivate organizations across the industry – Internet service providers, hardware makers, operating system
vendors and web companies – to prepare their services for IPv6 to ensure a successful transition as IPv4
addresses run out.”

Overall Impressions
IPv6
Awesome ... As Soon As Websites Deploy It.
Goodbye DHCP!
IPv6 on my Motorola Droid? Wow.
Not on my PS3. BOO!

Overall Impressions
Check your Firewall configuration. May need to reconfigure when you
enable IPv6.
Most software (Samba, BIND, IRC, etc...) is all ready to go.
You may need to run Dual-Stack (IPv4 & IPv6) for some applications.