Transcript Irish IPv6 Task Force Introduction to IPv6 Fundamentals Irish IPv6 Task Force -

Irish IPv6 Task Force
Introduction to IPv6
Fundamentals
Irish IPv6 Task Force - http://www.ipv6.ie/
Irish IPv6 Task Force
IPv6 Training Slide-sets
1. The Bigger Picture: Why is IPv6 so Important?
2. Introduction to IPv6 Fundamentals (technical) <This slide set is second in a series
3. IPv6 Deployment & Strategy (technical)
4.
The Business Case for IPv6
5. Mobile IPv6 (technical)
6. IPv6 Quality of Service (technical)
7. IPv6 Security (technical)
Irish IPv6 Task Force - http://www.ipv6.ie/
Presentation Structure
• Introduction
• Why IPv6 was designed.
• IPv6 Addressing (format, types and policy).
• How IPv6 interacts with other layers
• Transition mechanisms.
• The current state of IPv6.
Irish IPv6 Task Force - http://www.ipv6.ie/
Introduction
Irish IPv6 Task Force - http://www.ipv6.ie/
Introduction
• Introduction to IPv6 technical details.
• Only overview, not comprehensive.
• Further information in complementary sources.
• Will also touch on policy/history where it
influences technical matters.
Irish IPv6 Task Force - http://www.ipv6.ie/
Why IPv6 was designed.
Irish IPv6 Task Force - http://www.ipv6.ie/
IPv4: Late 80s/Early 90s
• Hosts went from 10,000 to 100,000 between 1987 to
1989.
• IP space was classful:
− 126 class A of 16M hosts,
− 16K class B of 64K,
− 2M class C of 253.
• Concern about routing and addressing.
• By 1993, people reckoned there was < 1year worth of
address space left.
• Lead to CIDR: Classless Interdomain Routing.
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CIDR
• Class A, B and C had network/host boundary.
• CIDR puts the boundary on any bit.
Net
First
Net Mask
Address
Prefix
Length
MIT
18.0.0.0
TCD
134.226.0.0 255.255.0.0 /16
Schools 87.32.0.0
255.0.0.0
/8
255.240.0.0 /12
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NAT
Network Address Translation made it possible to
use fewer addresses. Idea: rewrite addresses using
rules. Allows use of private address space.
• Connection from private block is made.
• Allocate public address/ports, record in rules.
• Outgoing packets have private address and port
replaced.
• Incoming packets have public address and port
replaced.
Irish IPv6 Task Force - http://www.ipv6.ie/
IPv4 Today
• NAT/CIDR have bought IPv4 (too much?) time.
• IPv4 has developed new problems since.
• Security (spam, viruses, botnets, exploits, …)
• Routing (scalability, stability, multihoming)
• NAT (inhibitor, robustness, performance, cost)
• Politics/Market (scarce resources, must be (seen to
be?) distributed fairly)
Irish IPv6 Task Force - http://www.ipv6.ie/
IPv6
• OSI 7 Layer Model.
• TCP/IP spans many layers.
• IP is layer 3.
• IPv6 is a new layer 3.
• So we keep TCP, UDP, HTTP, …
• Need to update the glue between layers too.
Irish IPv6 Task Force - http://www.ipv6.ie/
Major Changes
• Bigger addresses (128 bit up from 32 bit).
• Better extensibility (extension headers).
• Built in autoconfiguration (DHCP/PPP still possible).
• Mandatory IPsec.
• More integrated multicast.
• ARP replaced with Neighbour Discovery.
Irish IPv6 Task Force - http://www.ipv6.ie/
IPv6 Addressing (format,
types and policy)
Irish IPv6 Task Force - http://www.ipv6.ie/
Addresses
• Compromise between variable and 64 bit.
• 128 bit addresses: 340282366920938463463374607431768211456.
• In practice you loose space to structure.
• 64 bits for hosts: enough for biggest subnets?
• 64 bits for networks: enough to make aggregation easier ?
•Long, so written in 8 hex quads.
•Shortcuts permitted.
Irish IPv6 Task Force - http://www.ipv6.ie/
Example Address
• 2001:0db8:0010:0300:0000:0000:0ae2:510b
− Long version.
• 2001:db8:10:300:0:0:ae2:510b
− Omit leading zeros.
• 2001:db8:10:300::ae2:510b
− Replace run of zeros with ::
• 2001:db8:10:300::10.226.81.11
− Can write end as IPv4 address.
Irish IPv6 Task Force - http://www.ipv6.ie/
Structured Addressing
• 2001::/16 Chunk of production address space
• 2001:770::/32 = HEAnet (ISP prefix)
• 2001:770:10::/48 = TCD (organisation prefix)
• 2001:770:64:300::/56 = Maths (dept prefix)
• 2001:770:64:301::/64 = Wireless (subnet)
This structure is dictated by policy at various levels, rather than
being hardwired Into the protocol. This allows the policy to be
adjusted to balance the needs of various stakeholders (users,
network administrators, ISPs, governments, hardware/software
vendors, …)
Irish IPv6 Task Force - http://www.ipv6.ie/
Special Addresses
• :: the unspecified address.
• ::1 localhost/loopback.
• fe80::/10 link-local addresses.
• ff00::/8 multicast addresses.
• Multiple addresses on each network card on each
machine now normal!
Irish IPv6 Task Force - http://www.ipv6.ie/
How IPv6 interacts with
other layers.
Irish IPv6 Task Force - http://www.ipv6.ie/
Communication Modes
• Unicast: Destined to a single machine (normal).
• Broadcast: Destined to all machines (ARP).
• Multicast: Destined to all in a particular group (IP TV,
ND).
• Anycast: Destined to any one of a particular group
(DNS Root Servers, 6to4).
Irish IPv6 Task Force - http://www.ipv6.ie/
Autoconfiguration
• Generate host-id and form link-local.
• Check link-local is unique.
• Now we can talk IPv6.
• Multicast router solicitation to get prefix(es).
• Global address(es) = prefix(es) + host-id.
• Do duplicate address detection.
• Doesn’t have to be used: manual, DHCPv6, PPP and
privacy addressing also possible.
Irish IPv6 Task Force - http://www.ipv6.ie/
Address Scope
• Might have same link-local address on each interface.
• How do we know which one?
• Addresses can have scope.
• E.g. two interfaces eth0 and eth1
• fe80::2b0:d0ff:fef4:c6c5%eth0
• fe80::2b0:d0ff:fef4:c6c5%eth1
• No need for scope on global addresses.
Irish IPv6 Task Force - http://www.ipv6.ie/
Header Differences
• Bigger addresses.
• Drop uncommonly used features (fragments, IP
options).
• Drop fields that are redundant (header length,
checksum).
• Rename some fields to better represent modern
usage.
• 64 bit alignment to help hardware guys.
• Add a new flow label.
Irish IPv6 Task Force - http://www.ipv6.ie/
Header Flexibility
• Main header is for forwarding packet.
• Minimum necessary fields included.
• New types of header may be chained together leading
to TCP, UDP or ICMP.
• Used for mobility, security, tunnels, and other
advanced features.
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Glue
• ICMP closely linked with IP, so new ICMPv6.
• ICMPv6 includes Neighbour Discovery to replace ARP.
• Most layer 2 glue is included in details of neighbour
discovery.
• Changes to higher layers relatively small.
• TCP/UDP “pseudo-header” for checksums.
• Update protocols that embed IPv4 addresses.
Irish IPv6 Task Force - http://www.ipv6.ie/
Transition Mechanisms
Irish IPv6 Task Force - http://www.ipv6.ie/
Transition Mechanisms
• We have a large IPv4 network.
• We want a large IPv6 network.
• IPv4 only hardware, software and people.
• How to get IPv6 working around this?
• A lot of effort on Transition Mechanisms.
Irish IPv6 Task Force - http://www.ipv6.ie/
Transition Mechanisms
• Several broad strategies.
• Dual stack: run both IPv4 and IPv6.
• Tunnelling: hide IPv6 inside IPv4/UDP/…
• Translation: convert IPv6 into IPv4.
• Proxies: Someone speaks IPv6 on your behalf.
• Too many to discuss all.
Irish IPv6 Task Force - http://www.ipv6.ie/
Transition Examples
• Vista/OS X/Linux/BSD all run dual-stack.
• Point-to-point tunnels to get around legacy
equipment.
• Automagic tunnelling (6to4, Teredo) for end users in
IPv4 only networks.
• Proxies already common (web proxy, DNS server, SMTP
server, …)
• Translation uncommon, maybe for legacy apps?
Irish IPv6 Task Force - http://www.ipv6.ie/
The current state of IPv6.
Irish IPv6 Task Force - http://www.ipv6.ie/
Potted Local History
• 1999-2001: Small scale academic experiments.
• 2002: Native gigabit IPv6 from HEAnet to TCD.
• 2003: IPv6 addresses in .ie zone.
• 2004: IPv6 server for .ie zone.
• 2005: National IPv6 centre established.
• 2006: 6bone retired in favour of full IPv6 net.
• 2007: ???
Irish IPv6 Task Force - http://www.ipv6.ie/
IPv6 Today
• The basics are done.
• Deployment underway, not yet widespread.
• Core/edge ready, corporate/ISP waiting.
• Policy/standards continuing to evolve.
• Considering IPv6 in lifetime of current planning,
projects & purchases considered prudent.
Irish IPv6 Task Force - http://www.ipv6.ie/
Summary
• IPv6 just replaces IP layer in TCP/IP.
• Fixes problems, particularly addressing.
• Eases features such as mobility, security, …
• Transition mechanisms to help deployment.
• Standards, policy and network in place.
• Someway to go before full deployment.
• Continuing to evolve as living protocol.
Irish IPv6 Task Force - http://www.ipv6.ie/
Acknowledgements
This presentation includes some material originally developed for
presentations at Doolin Tech Talks, RIPE, HEAnet and TCD.
Irish IPv6 Task Force - http://www.ipv6.ie/
Contact
Mícheál Ó Foghlú
Research Director
Telecommunications Software & Systems Group
Waterford Institute of Technology
Cork Road
Waterford
Ireland
+353 51 302963 (w)
[email protected]
http://www.tssg.org
http://www.ofoghlu.net/log (Personal Blog)
Irish IPv6 Task Force - http://www.ipv6.ie/
Further Information
Web Sites:
•
National Irish IPv6 Centre http://www.ipv6-ireland.org
•
Irish IPv6 Task Force http://www.ipv6.ie
•
IPv6 ePrints Server (Public Documents) http://www.6journal.org/
•
IPv6 Dissemination (Public Training) http://www.6diss.org/tutorials/
Individual Documents/Presentations:
•
http://arstechnica.com/articles/paedia/IPv6.ars/1 (Iljitsch van Beijnum, 7th March 2007)
•
http://bgp.potaroo.net/ipv4/ (Geoff Huston APNIC, 2006)
•
http://www.6journal.org/archive/00000261/02/WWC_IPv6_Forum_Roadmap__Vision_2010_v6
.pdf (IPv6 Forum Roadmap & Vision, 2006)
•
http://colab.cim3.net/file/work/Expedition_Workshop/2005-1206_Advancing_Information_Sharing_And_Data_Architecture/IPV6/NIST%20ipv6-doc-eaiv4%2012062005.ppt (Doug Montgomery NIST, 2005)
Irish IPv6 Task Force - http://www.ipv6.ie/
Further Information
Individual Documents/Presentations Contd:
•
MIPv6 Linux Software ( MIPL )
−
•
www.mobile-ipv6.org
MIPv6 IETF charter
−
http://www.ietf.org/html.charters/mip6-charter.html
Irish IPv6 Task Force - http://www.ipv6.ie/
Thank you!
This presentation has been shared under the
Creative Commons Attribution 2.0 UK:
England & Wales Licence
(http://creativecommons.org/licenses/by/2.0/uk)
by the Irish IPv6 Task Force
(http://www.ipv6.ie)
Please acknowledge this source if you use it for
free or for profit
Irish IPv6 Task Force - http://www.ipv6.ie/