Ip4 vs ip6
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Transcript of Ip4 vs ip6
• Internet Protocol version 4 (IPv4, or just “IP”)– First developed for the original Internet (ARPANET) in spring
1978– Deployed globally with growth of the Internet– Total of 4 billion IP addresses available– Well entrenched and used by every ISP and hosting
company to connect customers to the Internet– Allocated based on documented need
• Internet Protocol version 6 (IPv6)– Design started in 1993 when IETF forecasts showed IPv4
depletion between 2010 and 2017– Completed, tested, and available for production since 1999– Total of
340,282,366,920,938,463,463,374,607,431,768,211,456 IP addresses available
– Used and managed similar to IPv4
IP version
IPv4 IPv6
Deployed 1981 1999
Address Size
32-bit number 128-bit number
Address Format
Dotted Decimal Notation: 192.0.2.76
Hexadecimal Notation: 2001:0DB8:0234:AB00:0123:4567:8901:ABCD
Number of Addresses
232 = 4,294,967,296 2128 = 340,282,366,920,938,463,463,374,607,431,768,211,456
Formate/ Length
not Yes
Internet Protocol Transports a datagram from source host to
destination, possibly via several intermediate nodes (“routers”)
Service is:Unreliable: Losses, duplicates, out-of-order
deliveryBest effort: Packets not discarded capriciously,
delivery failure not necessarily reportedConnectionless: Each packet is treated
independentlyData gram: consist of variable header and a
variable data field
IP Datagram Header header and data
VERS HLEN TOS TOTAL LENGTH
IDENTIFICATION FLAG FRAGMENT OFFSET
TTL PROTOCOL CHECKSUM
SOURCE ADDRESS
DESTINATION ADDRESS
OPTIONS (if any) + PADDING
0 4 8 16 19 31
IPv6 availabilityGenerally available with (new) versions of
most operating systems.
BSD, Linux 2.2 Solaris 8
An option with Windows 2000/NT
Most routers can support IPV6
IP v6 - Version NumberIP v 1-3 defined and replacedIP v4 - current versionIP v5 - streams protocolIP v6 - replacement for IP v4
During development it was called IPng Next Generation
Why Change IP?Address space exhaustion
Two level addressing (network and host) wastes space
Network addresses used even if not connected to Internet
Growth of networks and the InternetExtended use of TCP/IPSingle address per host
Requirements for new types of service
Why Change IP?Address space exhaustion
Two level addressing (network and host) wastes space
Network addresses used even if not connected to Internet
Growth of networks and the InternetExtended use of TCP/IPSingle address per host
Requirements for new types of service
IPv6 HeaderVERS 4bit PRIO 4b
Hop Limit 8b
Flow Label 24b
Payload Length 16b Next Header 8b
1 byte1 byte 1 byte 1 byte
6 for IPv6
Source Address (128 bits - 16 bytes)
Dest. Address (128 bits - 16 bytes)
IPv6 Header FieldsVERS: 6 (IP version number)Priority: will be used in congestion controlFlow Label: experimental - sender can
label a sequence of packets as being in the same flow.
Payload Length: number of bytes in everything following the 40 byte header.
IPv6 Header FieldsNext Header is similar to the IPv4 “protocol”
field - indicates what type of header follows the IPv6 header.
Hop Limit is similar to the IPv4 TTL field (but now it really means hops, not time).
IPv6 Addresses128 bits longAssigned to interfaceSingle interface may have multiple unicast
addressesThree types of address
ADVANTAGE • Larger add. Space• Better header format• New option• Supported more security and resource allocation
Types of addressUnicast
Single interfaceDelivery to single interfaceEg. Global unicast add , link local add, site local add
AnycastSet of interfaces (typically different nodes)Delivered to any one interfacethe “nearest”
MulticastSet of interfacesDelivered to all interfaces identifiedCommnly used scope include link local add, site local
MulticastingAddresses that refer to group of hosts on one
or more networksUses
Multimedia “broadcast”TeleconferencingDatabaseDistributed computingReal time workgroups
Example Config
20
Broadcast and Multiple UnicastBroadcast a copy of packet to each network
Requires 13 copies of packetMultiple Unicast
Send packet only to networks that have hosts in group
11 packets
IPv4-Mapped IPv6 AddressIPv4-Mapped addresses allow a host that
support both IPv4 and IPv6 to communicate with a host that supports only IPv4.
The IPv6 address is based completely on the IPv4 address.
Works with DNSAn IPv6 application asks DNS for the address
of a host, but the host only has an IPv4 address.
DNS creates the IPv4-Mapped IPv6 address automatically.
Kernel understands this is a special address and really uses IPv4 communication.
IPv4-Compatible IPv6 AddressAn IPv4 compatible address allows a host
supporting IPv6 to talk IPv6 even if the local router(s) don’t talk IPv6.
IPv4 compatible addresses tell endpoint software to create a tunnel by encapsulating the IPv6 packet in an IPv4 packet.
Mobility Support in IPv6
Mobile computers are becoming commonplace.Mobile IPv6 allows a node to move from one link to
another without changing the address.Movement can be heterogeneous, i.e., node can move
from an Ethernet link to a cellular packet network.Mobility support in IPv6 is more efficient than
mobility support in IPv4.There are also proposals for supporting micro-
mobility.
Auto-configuration in IPv6Link-local prefix concatenated with 64-bit MAC
address. (Autonomous mode)
Prefix advertised by router concatenated with 64-bit MAC address. (Semi-autonomous mode.)
DHCPng (for server modes)Can provide a permanent address (stateless mode)Provide an address from a group of addresses, and
keep track of this allocation (stateful mode)Can provide additional network specific information.Can register nodes in DNS.
Big users: Germany (33%), EU (24%), Japan (16%), Australia (16%)