This value will always be 64 bits in length, and in the case of an Ethernet interface, the identifier is dynamically created from the MAC address of the interface. Identifying An Interface In IPv6Įvery interface on a given IPv6 link has to have a unique identifier, and once again the name is the recipe with these interface identifiers. Leading zero compression: Perform as often as you like in an address. Zero compression: Allowed only once per address. If the block is all zeroes, you have to leave one zero. Leading zeroes in any 16-bit field can be dropped, but each block you do this with must have at least one number remaining. The key rule: you can only do this zero compression once in an IPv6 address. If you have consecutive fields of zeroes, they can be expressed with two colons. Zero Compression And Leading Zero Compression With IPv6, our non-compressed address has eight sections of four hex values, separated by a total of seven colons. There are some IPv4 fields that are not represented in IPv6: source address, destination address – they’re now 128 bits.next header – Equivalent to IPv4’s Protocol field.hop limit – Roughly equivalent to IPv4’s Time To Live (TTL) field. Every hop decrements this counter by one, and when that counter hits zero - the “time to live” becomes the time to be discarded.payload length – IPv4’s equivalent is the Total Length field.This also helps with QoS, allowing us to prioritize traffic flows rather than individual packets.

flow label – No equivalent in IPv4, this field allows a packet to be labeled as part of a particular flow.The “traffic class” name comes from this field’s ability to allow us to assign levels of importance to a packet via QoS. traffic class – In IPv4, this was the Type Of Service (TOS) field.QoS capabilities with IPv6 are far greater, due to many more values within the IPv6 header.DHCP is still available, but IPv6 nodes can assign themselves an address without the help of a DHCP server via autoconfiguration.IPv6 offers greater security capabilities.IPv6 was designed with route aggregation/summarisation in mind.IPv6 addressed are 128-bits in size, offering a hugh amount of addresses.

Ipv6 address compression rules