Learn About Differences in Addressing Between IPv4 and IPv6

Learn About Differences in Addressing Between IPv4 and IPv6

1. Differences between IPV4 and IPV6

   • Its important to understand that IPv6 is much more than a extension of IPv4 addressing. it covers a lot of more than simple address space extension from 32 to 128 bits
     • More efficient routing. IPv6 routers no longer have to fragment packets.
     • IPV4 has no way to distinguish delay-sensitive packets from bulk data transfers, requiring extensive workarounds, but IPv6 does
     • Elimination of NAT for the increases address size from 32 bits to 128 bits
     • Network layer security built-in(IPsec). Security, always a challenge in IPv4, is an integral part of IPv6.
     • Key IPv4 and IPv6 Comparisons
     • Improve header structure with less processing overhead
     • Many of fields in the IPv4 header were optional, IPv6 eliminates these fields.
       • Header IPV4
         • Header IPV6

2. IPv6 Address Notation

   • IPv6 address are written very differently than IPv4 notation. So, in IPv6 the 128 bits in the Ipv6 address: * Are written as eight 16 bit-hexadecimal blocks separed by colons. *Use abbreviations to simplify the notation. *Omit (optionally) leading zeroes. *Use double colons to replace consecutive zeros, but never than once per address.
     • Example

3. IPv6 Prefix Notation

   • This is the longest match rule, and ensures that a 64-bit prefix is preferred over a 32 bit prefix; when the first 32 bits of a packets destination address are the same in both table entries. Prefixes used for routing are defined in IPv6 by RFC 4291. So the IPv6 address:
     • 2bfc:0000:0000:0000:0217:cbff:fe8c:5c85/64.....Has a 64-bit prefix of 2bfc:0000:0000:0000:

4. IPv4 and IPv6 Address Usage Compared

   • The expanded address space a certainly one of the most distinctive features of IPv6. Table show some of the major differences between IPv4 address types and their use in IPv6

5. IPv6 Address Allocation and Types

   • In the same way as IPv4, organizations and end users get IPv 6address allocations from their ISPs. Networks devices: *Any subnet with a prefix of /64 or shorter is supported. *Initial address assignments shoulds allow for a site to establish multiple subnets.*Users should allow a user or site to easily obtain additional IPv6 address space for additional subnets. Types: Unicast addresses: Addresses used to send packets to one specific address. Multicast addresses: Used to send to every member of a specific group. Anycast adresses: Used to send to any one member of a specific group.

6. Notable IPv6 Addresses

   • Summary table.

7. Ipv6 Host Addressing

   • *Unicast Address. *Link-local on each interface with FE00::/7. *Additional unicast address for each interface. *Loopback address ::!. *Multicast addresses FF01::1, FF02::! . *The solicited-node address for each assigned unicast address. *The multicast addresses of any groups the host has joined.

8. Ipv6 router

   • +Unicast adddresses: *Link-local address on each interface, *Additional unicast addresses for each interface. +Anycast addresses: *Subnet-router anycast addressfor each subnet established, *Opcionally, additional anycast addresses. All IPv6 router interfaces listen for traffic on the following multicast addresses: FF01::1, FF01::2, FF02::1, FF02::2, FF05::2, the solicited-node address for each assigned unicast address and the multicast addresses of any groups the router has joined.

9. IPv6 Protocols

   • IPv6 does not use ARP to map network layer IPV4 addresses to link level addresses. Also IPv4 ICMP has been redone as ICMP v6. With the assistance of ICMPv6, IPv6 can discover neighbors and routers through special neighbor discovery and router advertisement messages. This simplifies host configuration on LANs and lets devices find default routers on their own. ICMPv6 can automatically determine path MTU limitations, and notify the sender if this is not respected.

10. IPv6 Subnetting

    • Subnneting is a way for users to take an assigned IP address space and partition it to meet their specific needs. For example if an organization has two office locations, one large and another small, the IP address space can be subnetted so that the host get the adesses they need and traffic can be efficiently handled internally without concerning the global public internet. When subnetted an IPv6 address consists of three parts: *The global routing prefix, *The subnet identifier, *The interface identifier or "host address".

11. Junos Address Aware

    • Is an addressing and tunneling software portfolio for the MX Series router that helps network operators conserve and extend their IPv4 address pool, ensure IPv4/IPv6 coexistence, and pragmatically transition to IPv6 in a cost-effetive and low risk manner. Its available as a software license for MX Series MS-MPC and MS-MIC Service Cards.

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