IPv6, what it is, what it does, and how it helps.

Article by Nathan Zero

The Point of IPv6

Probably the most advertised feature of IPv6 may be the larger address space. If you've read anything about IPv6, the chances are you realize that it increases the address size from 32 bits to 128. This is ample for everyone ever born to possess a private network bigger than the present Internet. Even if all you own (including stuff that don't contain any electronics) had its own IPv6 address, you would then still not be exceeding a little fraction of the address space.

This really is quite important since it could make routing easier. Routers typically connect a relatively small number of networks together. The simplest case is the home router, which connects your local network to the Internet. For every packet it receives, it has to do among three things: drop it, forward it to the internal network, or forward it to the external network.

For a typical home network, this really is quite a simple decision: When the destination address is in among the reserved private ranges, send it inside; otherwise send it. Big commercial routers have to make a lot more complex decisions. Because the mid '90s, when IPv4 addresses started to be seen as an scarce resource, they have been allocated in 8-bit ranges. This means that you may get three adjacent blocks on completely different networks. With this particular allocation scheme, you will find 2^24 possible networks, along with a router needs to be in a position to choose which connection along which a packet destined for any of them ought to be sent. 2^24 is a little under 17 million. Fortunately, many of these is going to be simpler, so you can combine their entries, but it's still hard to make routing decisions.

With IPv6, there are enough addresses now that every country or major network could be assigned a wide range. It can then assign subranges within that to networks that it connects to, and so on. This hierarchical assignment (theoretically, at least) simplifies routing decisions.

One of the leading complaints about IPv6 originates from people who think NAT is security and confuse "routable" with "accessible." With IPv4, most home users (and just about all mobile users) use network address translation (NAT). Your computer has a private IP address, and the router includes a public one. Every connected port on your private IP is mapped to a port on the public IP address. This doesn't provide any security. Most NAT implementations also default to denying connections originating outside, although some will forward those to a designated default host.

The policy of denying externally-originating connections provides security, but that's supplied by the firewall area of the router and is not intrinsic to NAT. Most non-NAT firewalls is going to do the same.

Just because your pc comes with an externally routable IPv6 address does not necessarily mean that it's accessible. The firewall device that you connect for your Internet connection still defines a policy of who are able to connect. Given the quantity of hacks used to penetrate NATs to create such things as Voip work, it's surprising that anyone still thinks it adds security, but apparently some perform.

The most advertised feature of IPv6 is the larger address space. If you've read anything about IPv6, then you probably know that it increases the address size from 32 bits to 128. This really is ample for everyone ever born to possess a private network larger than the current Internet.

The Day The Routers Died... a song performed by the secret-wg in the closing plenary of the RIPE 55 conference a long long time ago i can still remember when my laptop could connect elsewhere and i tell you all there was a day the network card i threw away had a purpose - and worked for you and me.... But 18 years completely wasted with each address we've aggregated the tables overflowing the traffic just stopped flowing.... And now we're bearing all the scars and all my traceroutes showing stars... the packets would travel faster in cars... the day....the routers died Chorus (ALL!!!!!) So bye bye, folks at RIPE 55 Be persuaded to upgrade it or your network will die IPv6 just makes me let out a sigh But I spose we'd better give it a try I suppose we'd better give it a try Now did you write an RFC That dictated how we all should be Did we listen like we should that day Now were you back at RIPE fifty-four Where we heard the same things months before And the people knew they'd have to change their ways.... And we - knew that all the ISPs Could be - future proof for centuries But that was then not now Spent too much time playing WoW ooh there was time we sat on IRC Making jokes on how this day would be Now there's no more use for TCP The day the routers died... Chorus (chime in now) So bye bye, folks at RIPE 55 Be persuaded to upgrade it or your network will die IPv6 just makes me let out a sigh But I spose we'd better give it a try I suppose we'd better give it a try I ...

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Orignal From: IPv6, what it is, what it does, and how it helps.