IPV6 through my knowledge

IPV6

A few years ago, cisco some other vendor began the push toward ip version 6.the main reason for the push was the limited number of ipv4.some work around to this problem have become so popular, NAT among them, that the move to ipv6 addresses slowed greatly.
One reason is that cisco feels network security is tighter when there are no “middlemen” such as dhcp and nat between two end points. This is possible because ipv6 uses 128-bit addresses rather than ipv4 32-bit addresses. Ipv6 addresses consist of eight 16-bit hex fields. And also has other important uses. Mobile ip, which allows end systems such as global positioning system (GPS). Ip phone to move without losing connectivity is built into ipv6, as is ip security (ipsec). (ipsec is compatible with ipv4 but is built in to ipv6).

There are 8 header fields in ipv6.
•Version – this is set to “6” in ipv6
•Traffic class-in ipv4, this was the type of services(tost)
•Flow label – no equivalent in ipv4, this allow packet to be labelled as part of particular flow.
•Payload length – ipv4 equivalent is the total length field.
•Hop limit – roughly equivalent to ipv4 protocol field.
•Source add , destination add – they’re now 128 bit.

There are some ipv4 fields that are not represented in ipv6:
•Header length
•Identification
•Flags
•Fragments offset
•Header checksum

IPV6 ADDRESSES FORMAT

Typically ipv4 add : 129.14.12.200
Typically ipv6 add: 1029:9183:81AE:0000:0000:OAC1:2143:091B

As you can see ipv6 isn’t exactly just taking two more octet ipv4 add.



Rules:

ZERO COMPRESSION AND LEADING ZERO COMPRESSION

If you have consecutive fields of zeroes, they can be expressed with two colons,. It doesn’t matter if you have two fields or eight, you can simply type two colons and that will represent all of them the key here is that you can only do this once in an ipv6 address. This referred to as zero compression,

EXAMPLE:
ORIGINAL FORMAT: 1234:1234:0000:0000: 0000:0000:3456:3423
USING ZERO COMPRESSION: 1234:1234::3456:3423

Rules is that leading zeroes in any 16bit fields can be dropped, but each block you do this must have at least one number remaining. That is if the block is all zeroes, you have to leave one zero this is leading zero compression.

LEADING ZERO COMPRESSION

We have four different fields that have leading zeroes. The address could be written out ads it is or drop the leading zero.

EXAMPLE:
ORIGINAL FORMAT: 1234:0000:1234:0000:1234:0000:1234:1234
LEADING ZERO COMPRESSION: 1234:0:1234:0:1234:0:1234:1234

There is no problem with using zero compression and leading zero compression in the same address.

ORIGINAL FORMAT: 1111:0000:0000:1234:0011:0022:0033:0044
With ZERO AND LEADING ZERO COMPRESSION: 1111:: 1234:11:22:33:44

Zero compression uses the double-colon to replace the second and third block of numbers which were all zero leading zero compression replace “00” at the beginning of each of the last four block. Just care full my friend....

Ipv6 offer two kinds of local addresses link-local, and site local. Site local addresses allow devices in the same organization or site exchange data. Site local are ipv6 equivalent to ipv4 private private address classes since hosts using them are able to communicate with each other throughout the organization, but these add cannot be used to reach internet host or hosts on a remote site. Link-local add have a smaller scope than site-local they’re local to be a physical.


IPV6 ADDRESSES BY THEIR INITIAL BITS.

•001 – global address
•1111 1111 – multicast (FF)
•1111 1110 11 – site local (FEC0)
•1111 1110 10 – link local (FE80)

::x.x.x or 0:0:0:0:x.x.x.x – ipv4 compatible address. Any ipv6 add with the first 96bit set to zero is an ipv4-compatible add. I used zero compression in the first representation of that range, and leading zero compression for the second.

IPV4 – IPV6 COMPATIBLE ADDRESSES
If you see an address with a great many zeroes at the beginning , it may well be an ipv4-compatible ipv6 address. Such as address is going to have zeroes for the first bits 96bits. Which make zero compression even better the rest of the bits will be hexadecimal expression on ipv4 add.

IPV6 ADD TO CONVERT: ::D190:4E71

Note:The double-colon is zero compression in action, so now we need to convert the lower 32-bit into decimal

D1 = 13 UNIT 16, 1 UNIT 1 = 209
90 = 9 UNIT 16, 0 UNIT 1 = 144
4E = 4 UNIT 16, E UNIT 1 = 78
71 = 7 UNIT 16, 1 UNIT 1 = 113
Answer: 209.144.78.113
How it happen like: D1 = 13x16= 208, 1x1= 1 (208+1=209)

You know what a multicast is , and that ipv4 multicast addresses are class D addresses. With a first octet value of 224-239. The ipv6 multicast range is much larger my friend, but just easy to remember. Any address that begin with “1111 1111” or “FF” in hex, is multicast address full prefix being FF00::/8 .


WHAT THE HOST SOLICITATING?

It needs additional configuration information from a router, which will be sent in the form of a router advertisement (RA). (router will also transmit RA without an express solicitation.) the router attaches the network prefix to the host link local address, which result in the host full ipV6 address complete with network prefix.



IPV6 ROUTING ON CISCO ROUTERS

•Rip for ipv6 – actual name is RIPNG (new generation)
•EIGRP FOR IPV6
•OSPF V3 (version 3, defined in RFC2740)
•STATIC ROUTERS ARE STILL BGP V4 (MPBGPVERSION 4 OR simply MPBGP)
One protocol you learned in your CCNA level of course me. Studies didn’t quite make the cut there’s no such thing as IGRP for ipV6.
To enable a cisco ipV6 routing capabilities

Run:
Ip cef
Ipv6 cef
ipv6 unicast-routing

if you want to learn more just search it.. or else you want me to teach you one on one... :p