Size, Number of addresses, Comparison to IPv4, header format, Addressing Format, zero compression, Ports, network prefix, address allocation, Multicast instead of Broadcast, auto configuration,
2. IPv6
Internet Protocol version 6 (IPv6) is the most recent version of
the Internet Protocol (IP), the communications protocol that
provides an identification and location system for computers on
networks and routes traffic across the Internet. IPv6 was
developed by the Internet Engineering Task Force (IETF) to deal
with the long-anticipated problem of IPv4 address exhaustion.
IPv6 is intended to replace IPv4.
3. Why IPv6?
• IPv4 32 bit address = 4 billion hosts
• CIDR, VLSI were developed to fix the shortage of IPv4 address.
• The rising of Internet connected device, IoT, IoE and appliances
will eventually deplete the IPv4 address space.
• IP is everywhere.
• So, only compelling reason: MORE IP ADDRESSES.
4. IPv6 address
• IPv6 is 128 bit.
• It has 2^128 addresses.
• IPv4 is 32-bit.
• It has 2^32 addresses.
6. Addressing Format
• 16 bit hexadecimal numbers.
• Separated by (:).
• Not case sensitive.
• Example:
2001:0db8:00bc:0000:0000:0000:0abc:1234
• 4 bits referred to as nibble.
• 16 bits referred to as word or quartet.
7. Zero’s Compression
• Leading zeros can be removed.
2001:0db8:00bc:0000:0000:0000:0abc:1234
2001: db8: bc:0000:0000:0000: abc:1234
2001:db8:bc:0000:0000:0000:abc:1234
8. Zero’s Compression
• Consecutive zeros can be removed or replaced with ::
2001:db8:bc:0000:0000:0000:abc:1234
2001:db8:bc: : : :abc:1234
2001:db8:bc::abc:1234
9. Zero’s Compression
• Consecutive zeros can only be removed once
2001:db8:bc:0000:0000:abc:0000:0000
2001:db8:bc::abc::
2001:db8:bc:0000:0000:abc::
2001:db8:bc::abc:0000:0000:
12. Network Prefix/Subnet Mask
• Same as CIDR in IPv4.
2001:db8:bc::abc:1234/64
2002::/16
• Mostly used in Routing.
• Computers will almost always use /64
13. Address Allocation
• 64 bits reserved for the interface ID
• 16 bits reserved for the end site
• 16 bits reserved for the service provider
• 32 bits reserved for service providers.
14. Multicast
IPv6 does not implement traditional IP broadcast, i.e. the
transmission of a packet to all hosts on the attached link using a
special broadcast address, and therefore does not define
broadcast addresses. In IPv6, the same result is achieved by
sending a packet to the link-local all nodes multicast group at
address ff02::1, which is analogous to IPv4 multicasting to
address 224.0.0.1.
15. IPv6 Auto Configuration
• A new host is turned on.
• Tentative address will be assigned to the new host.
• Duplicate Address Detection (DAD) is performed.
• First the host transmit a Neighbor Solicitation (NS) message to
the solicited node multicast address corresponding to its to be
used address.
• If no Neighbor Advertisement (NA) message comes back then
the address is unique.
• Address will be assigned to the new host.
16. IPv6 Auto Configuration
• The new host will send Router Solicitation (RS) request to the
all-routers multicast group.
• The router will reply Routing Advertisement (RA).
• The new host will learn the network prefix. E.g,
2001:1234:1:1::/64
• The new host will assigned a new address
NETWORK PREFIX+INTERFACE ID
• E.g, 2001:1234:1:1:310:BAFF:FE64:1D