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In theory, how IPv4 is better than IPv6? I need only advantages of IPv4 for study purposes.

In another words - what are the pros of IPv4?

HopelessN00b
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Cleankod
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4 Answers4

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  1. Simpler
    1. IPs a normal human might be able to remember.
    2. Less programming, less memory, etc.
  2. Familiarity
    1. Thousands (millions?) of Network and System Administrators already know it.
    2. Existing infrastructure supports it at almost every level already.
Chris S
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    hmmm, with that argument why did we ever upgrade from ipv2? – The Unix Janitor Feb 04 '12 at 00:47
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    That's one simplified half of an argument. IPv4 has a better advantage to disadvantage ratio than IPv2 did, which is why we're using it today. IPv6 only has a better ratio in edge cases currently, which it is rather rare yet. At some point it will have a superior ratio (except again in edge cases) and will become the norm, supplanting IPv4 to the same status as NetBEUI or IPX. – Chris S Feb 04 '12 at 04:09
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Legacy support is the only one I can think of. It's been implemented and re-implemented to the point that just about everything out there would support it properly so lowest-common-denominator cheap equipment shouldn't, in theory, screw it up.

IPv6 is compatible with IPv4 but it's not widespread enough to the masses to show bugs in implementations yet, in my opinion. I'm sure someone's Internet enabled doodad will bug out because of an issue with interacting on IPv6.

Bart Silverstrim
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    IPv6 is not compatible with IPv4 in any meaningful way. – Ben Jan 25 '12 at 17:00
  • IPv4 devices are supposed to work in IPv6 environments, unless I'm really mistaken. – Bart Silverstrim Jan 25 '12 at 17:20
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    You are. IPv4 devices won't work in an IPv6 environment unless there is also IPv4 (e.g. your router might advertise IPv6 routes while still operating a DHCP server for IPv4). – Tom Marthenal Jan 25 '12 at 18:18
  • I was thinking in particular of dual-stack implementations, so you're right that IPv6 itself isn't compatible, but many implementations (devices) are. There has to be a mechanism to convert IPv4 to IPv6 at the gateway if you don't convert. – Bart Silverstrim Jan 25 '12 at 18:44
  • The short of it is that if you have an IPv4 network you don't *need* to throw it out just because there are IPv6 devices or your upstream is converting as dual-stack devices will help with the transition and keep your old stuff compatible. But no, IPv6 itself is not like an extension to IPv4. – Bart Silverstrim Jan 25 '12 at 18:46
4
  • It's easier to read and remember.
  • Better supported
Lucas Kauffman
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  • Ever configured routers ? :p – Lucas Kauffman Jan 25 '12 at 14:26
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    I don't **have** to remember them, but I do remember lots of them by accident. I recognise countries when watching spammers in the Apache logs and even individual customers if I've dealt with them before. – Ladadadada Jan 25 '12 at 14:32
  • If you have a bunch of servers on a localnetwork you don't really implement DNS and then it is just easier to remember them sometimes. You know for instance it is 192.168.1.x. Now remembering that with IPv6 is... more challenging. – Lucas Kauffman Jan 25 '12 at 14:37
  • @Lucas: With regards to the `192.168.1.x` - for IPv6 it's just in the block `fc00::/7` ie the addresses starting with `fc00::` – Callum Rogers Jan 25 '12 at 17:39
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    Callum, not exactly. `fd00::`, for example, also falls within the ULA space (`fc00::/7`). – Tom Marthenal Jan 25 '12 at 18:16
  • It is my hope that they become easier to remember with time.. – user606723 Jan 25 '12 at 21:23
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  1. Simple to remember and to operate.
  2. Better support.
  3. Better platform, specially some high-profile firewall, that while most support ipv6 but don't give a crap about the administration but a bare minimum for ipv6.
  4. Widely supported (it is way important)
  5. Short (how's short better?. Simple, because we are transmiting 4 bytes instead of 8 bytes, and in some cases it count as a big overload of information). In fact, the ipv6 header is double than ipv4 header .
  6. IPV6 could be used for identify you and it is a bad thing. Most important companies, websites and some home users uses fixed IPV4 address but the rest uses dynamic address that are hard to identify and associate with a specific user, and other users relies on fake-ip (192.168.. 10.128..) thar protect it from Internet.

And the main point is that the switch from IPV4 to IPV6 lacks of a plan-b and right now, the migration is not working so well.

magallanes
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    It's true that the IPv6 header is twice the size, but it's still quite small. IPv6's packet formst was designed to be more easily processed by routers (RFC 2460). In addition, while the privacy issue is a big deal, it's overblown. There are practical solutions to it already, such as privacy extensions. Dynamic IPs are a hack, not a security solution. That fake IP stuff doesn't really make sense either. – Tom Marthenal Jan 26 '12 at 18:17
  • Can't we still NAT with IPv6? I know we don't *need* to, but we might just want. – pkoch Feb 01 '12 at 05:36
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    NAT is the devils work and breaks the end to end nature of the internet. Read those rfc's – The Unix Janitor Feb 04 '12 at 00:48