Transcript IPv6

IPv6 The Big Move:
Transition and Coexistent
Frenil V. Dand
Introduction
• IPv6 (Internet Protocol version 6) is the successor to
IPv4
• IPv4 is base on 32bits, with that its possible to
express 4,294,967,296 different values. Over half a
billion of those are unusable. Giving us 3.7 billion
possible addresses
• 5% of IPv4 are reaming
• IPv4 will run out by end 2011
• IPv6 supports about 340 undecillion (1036) addresses
340,282,366,920,938,463,463,374,607,431,786,211,456
•IPv6 adoption has been
slowed and IPv4 exhaustion
has bee prolonged by NAT
(Network Address Translation)
http://www.ipv6forum.com/
Advantages of IPv6
• Trillions of times more addresses.
• Easy to configure (Neighbor discovery and Stateless
autoconfig)
• Compatible with 3G and features that support greater
mobility
• Supports ad hoc networking
• More efficient usage of broadband, via Jumbograms
and Flow Label
• Leaner Headers (six removed and one new filed).
• More secure with mandatory IPSec
• Better Quality of Service (QoS)
• Allowing for many new possibilities
IPv6 Headers
How does IPv6 work?
• New 128-bit addressing represented by eight 16 bit hex
components divided by colons, X:X:X:X:X:X:X:X
• Last 64 bits are used for interface ID
• e.g. 2001:0DB8:C003:0001:0000:0000:0000:F00D
• Can be represented in shorter format by removing leading
zeros e.g. 2001:DB8:C003:1:0:0:0:F00D
• Further reduction by removing consecutive fields of zeros
using the double-colon :: option
• Double-colon can be used only once, because multiple
occurrences would lead to ambiguity
• e.g. 2001:DB8:C003:1::F00D
• Addresses are organized in a hierarchical manner to
facilitate:
- Scaling
- Aggregation
- Routing
• Aggregation is achieved by address prefix and the
organization of addresses into two levels- public
topology and interface identifier
• Smaller routing tables allows for increase routing
efficiency
• IPv6 supports three address types:
- Unicast Addresses: one-to-one (global, link local,
unique local, compatible)
- Multicast Addresses: one-to-many (also replaces
broadcast addresses)
- Anycast Addressed: one-to-nearest (allocated
from Unicast)
IPv6 Global Unicast Address
Generic Division of Unicast
Field Name
Prefix
Subnet ID
Interface ID
Size (bits)
Description
“n”
Global Routing Prefix: The network
ID or prefix of the address, used
for routing.
“m”
Subnet Identifier: A number that
identifies a subnet within the
site.
“128-n-m”
Interface ID: The unique identifier for
a particular interface (host or
other device). It is unique within
the specific prefix and subnet.
• Unicast will be used for majority of the traffic
• One-eighth of address is assigned to it
•2001:0DB8:C003:0001:0000:0000:0000:F00D
IPv6 Multicast and Anycast
• Multicasting allows for single device to send data to
group of recipient
• Format Prefix of 1111 1111
• Always begins with FF
Four bits are reserved for Flags.
Currently, first 3 of them are set to zero (unused)
Last bit is Transient.
Transient can be zero or one:
If T set to Zero, then multicast address is wellknown permanently assigned
If T set to One, then multicast address is not
permanently assigned
Scope ID
(16 different values from 0 to 15)
Currently defined values (in decimal)
0 = Reserved
1 = Node-Local Scope
2 = Link-Local Scope
5 = Site-Local Scope
8 = Organization-Local Scope
14 = Global Scope
15 = Reserved
Unicast
• Send
this to
one
address
Multicast
• Send
this to
every
member
of this
group
Anycast
• Send
this to
any
member
of this
group
• Send
this to
closest
member
of this
group
• Anycast addresses are new to IPv6
• Cross between unicast and multicast
• Allows datagrams to be sent to whichever router in a
group of equivalent router is closest
Autoconfiguration and Renumbering
• By default IPv6 host can configure a link-local
address for each interface
• Router discovery allows host to determine
addresses of routers, additional addresses, and
other configuration parameters
• Address autoconfiguration can only be performed on
multicast-capable interfaces
• 6 steps device takes for stateless autoconfiguration
1. Link-Local Address Generation- device generates a
link-local address
2. Link-Local Address Uniqueness Test- node tests to
ensure the address in not duplicated
3. Link-Local Address Assignment- device assigns
the link-local address to its IP interface
4. Router Contact- node next attempts to contact local
router for more information on continuing the
configuration
5. Router Direction- router provides direction to the
node on how to proceed
6. Global Address Configuration- host will configure
itself with its globally unique Internet address
IPv6 Transition and Coexistence
•
•
•
•
Very long and difficult process
IPv4 and IPv6 incompatible
Various technologies
Three categories :
– Dual Stack
– Tunneling
– Translation
• Dual Stack is a network stack that supports both IPv4
and IPv6 while sharing most of the code
• To work effectively must be implemented on all
routers in network
• Works by using two addressing schemes in parallel
• Requires more resources
• Tunneling is technique which consists of
encapsulating
• Allows IPv6 packets over IPv4 networks
• Require dual-stack at end of tunnel
• Three main tunneling techiques:
– IPv6 over IPv4 (6over4)
– IPv6 to IPv4 (6to4) automatic tunneling
– Tunnel Broker
• Three step of tunneling are:
– Encapsulation
– Descapsulation
– Tunnel management
• 6over4
– Embeds IPv4 in IPv6
– Not auto; needs network admin for end point
• 6to4 automatic tunneling
– Tunnel endpoint doesn’t require administrator
– IPv4 embedded in the last 32 bits
– IPv6 packets send over IPv4 network
• IPv6 Tunnel Broker
– 3rd party service or a vendor
• Teredo is extension of basic 6to4
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–
–
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Provides IPv6 connectivity behind NAT
Uses 3rd party relay service
Vista and Windows 7 running Teredo
Easy for average Internet users
• Intra-Site Automatic Tunnel Addressing Protocol
(ISATAP) similar to 6over4
– Automatic encapsulation by using virtual IPv6
– Used in enterprise network
• IPv4/IPv6 Translation
– Once considered as a last resort
– Not simple as it sounds
– Based on Stateless IP/ICMP and Network address
translation
– Only option of IPv6 transition that entirely remove
IPv4 addresses.
– Single-stack approach
• 6rd
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IPv6 Rapid Deployment
Big move help in residential consumer
Allows ISP to designate relay
Requires home hardware to support 6rd
Encapsulation of IPv6 inside IPv4 and send to ISP
Conclusion
• Not a overnight process
• Interoperability key
• IPv6 is going to internet and world of
communications to the next level
• Japan, China and other countries in Asia-Pacific
are already deploying and using IPv6
• 2008 Beijing Olympics was the widest use of IPv6
• Refrigerators can order groceries and taxis can
detect rain and message to headquarters
• And let’s not forget iPad, iPhone, and Android’s
• DOD and Federal Government already running
IPv6
The End
Questions?