Re: IPv6 cop tenekesine (trash can) :-)

["mustafa sahin" <mustafa.sahin@gmail.com>]

Merhaba,

Bence güncel durum ile amacı karıştırmamak lazım. Şu anda IPv6 geçişinde sorunlar olduğu kesin ve araştırma geliştirmelerin devam ettiği de kesin. Ancak IPv6'nın tek yararı ip adres aralığı diyen biri pek fazla teknik araştırma yapmamış vikipedia'lardan okumuştur diye düşünüyorum.

Ben 2 yıl önce yüksek lisans tezi olarak "ipv6 system migration" konusunu incelediğim de bile çok başarılı sonuçlar almıştım.
Uzak doğudaki IPv6 gelişimini takip edebilirsiniz. Aşaığdaki liste ülkelerdeki IPv4 adress dağılımını vermektedir. (Çin'in neredeyse Amerikanın 1/20si kadar adresi vardır.)

Country  Addresses 2007-01-01   Addr 2006-01-01

  US          1366.53 M            1324.93 M      United States
  JP           151.27 M             143.00 M      Japan
  EU           115.83 M             113.87 M      Multi-country in Europe
  CN            98.02 M              74.39 M      China
  GB            93.91 M              73.81 M      United Kingdom
  CA            71.32 M              67.43 M      Canada
  DE            61.59 M              51.13 M      Germany
  FR            58.23 M              45.16 M      France
  KR            51.13 M              41.91 M      Korea
  AU            30.64 M              26.87 M      Australia
  BR            19.27 M              17.17 M      Brazil
  IT            19.14 M              18.39 M      Italy
  ES            18.69 M              16.29 M      Spain
  TW            18.16 M              16.28 M      Taiwan
  NL            18.08 M              16.40 M      Netherlands



IPv6'nın avantajlarına gelince de:

Advantages of IPv6 over IPv4:

• Trillions of times more addresses will make it a mathematical certainty that in the future there will be orders of magnitude more devices with IPv6 than IPv4.
• IPv6 is easier to configure. Neighbor discovery finds other IPv6 systems and stateless (and stateful) autoconfiguration enable more automated set up of systems.
• IPv6 is compatible with 3G wireless (near) broadband and has other features that support greater mobility. There will be two billion mobile phones by 2006 and (at least) two addresses are required per mobile phone, so just enabling every mobile phone will require more IP addresses than are left with IPv4. Static addresses can also double battery life by not wasting power by checking whether a call is completed so the carrier can grab back the dynamic IP address, which wastes a great deal of power.
• IPv6 supports ad hoc networking, given the features just mentioned, enabling many different people, vehicles, weapons, etc. to all become networked when brought into proximity without special programming.
• IPv6 supports more efficient usage of broadband, both via the Jumbograms, in which packets increase from 64 KB in IPv4 to 4 GB in IPv6 (and soon 32 GB), and via the Flow Label, which enables network utilization to triple, from 27% efficiency to 81% efficiency.
• Headers in IPv6 are leaner, with six unnecessary fields removed, and one entirely new field added, enabling more efficient routing.
• IPSec is mandatory, bringing authentication (of users, of networks, and even of applications) to the entire IPv6 Internet and creating a "trusted bubble" according to Microsoft. IPv4 has no "trusted bubbles".
• Quality of Service is including in IPv6 headers, enabling premium pricing for guaranteed delivery, and prioritization of defense or other critical government Internet-based communications, even when networks are full. This is a big advance for actions against terrorist attacks or natural disasters, when virtually all communications channels are swamped and first responders and warfighters need prioritized packets to save lives.
• IPv6 allows for many new possibilities, including a new geolocation system that lines up IPv6 addresses with squares or hexagons across the earth's surface, in a new and novel latitude and longitude system that can be scaled down to nearly microscopic granularity, potentially
• IPv6 allows for the possible new boom in new and novel applications to enter into the world. In some cases, IPv6 tips the balance toward upgrading vs. keeping an older version, as with Microsoft Longhorn. In other cases, IPv6 will enable completely new applications and systems of applications, such as IPv6 enabled conference badges, bar codes, or RFID tags.
• There was also an IPv5, but it was not a successor to IPv4; rather, it was an experimental streaming protocol, intended to support voice, video, and audio.

Source: http://usipv6.com/what_is_ipv6.html

Son iki nokta:
_1_
IPv6 routing performansını düşürmek yerine getirdiği yeni header yapısı ile arttırmaktadır.

Faster routing:By using a simpler and more systematic header structure, IPv6 was supposed to improve the performance of routing. Recent advances in router technology, however, may have made this improvement obsolete.

_2_
Tunneling sadece bir geçiş aşamasıdır asla nihai amaç değildir. Tabiki overhead'i arttırmakta, ancak sadece geçiş aşamasında kullanılmaktadır. Native IPv6 networkler arttıkça artık IPv4 tunneling kullanacak o zaman da IPv4 kullanıcılarının paketleri IPv6 içinde gönderilecektir.


Özet olarak:
Şu anda IPv6 hızla gelişmiyorsa sebebi yararsız ve perfromansı küçük olması değil, aciliyetinin geçiş maliyetine göre daha az olmasıdır. Er ya da geç bu geçiş olacaktır.

"Regarded in IPv6 circles as the leader in
deployment, also has the strongest motivation: the millions of cell
phones, personal digital assistants and other devices its tech-savvy
population famously demands. The push to Web-enable them has required
the country to expand its available IP addresses, said Jun Murai, a
professor of environmental information at Keio University, in a phone
interview."


Iyi Günler...

27 Kasım 2008 Perşembe 21:35 tarihinde Adem <for-gmane@alicewho.com> yazdı:

Ve bir alinti daha:

http://en.wikipedia.org/wiki/IPv6#Disabling_IPv6_because_of_incompatibilities
"
Disabling IPv6 because of incompatibilities

Various forums on the Internet carry reports of
people disabling IPv6 because of perceived slowdowns
when connecting to hosts on the Internet.

This "slow-down" results from DNS resolution failures
due to faulty NAT 'routers' and other DNS resolvers
which improperly handle the AAAA DNS query.
These DNS resolvers just drop the DNS request
for AAAA records, instead of properly returning the
appropriate negative DNS response.
Because the request is dropped, the host sending the request
has to wait for a timeout to happen, thus causing a perceived
slow down when connecting to new hosts.
Since there is no result of the request that could be cached locally,
even if a DNS cache is running, the problem will persist for
identical lookups in the future.

"


"Adem" wrote:
"Timu EREN" wrote:
>
> performans'ı neden düşürdüğünü açıklarmısınız?

IPv6 vs. IPv4:

IPv4 adresleme icin 32-bit kullaniyor, IPv6 128-bit kullaniyor.
Yani, IPv6 4 kat fazla RAM harciyor, routerlerin routing tabloloari
IPv4'ün 4 kati. Router araclari (device'ler) genelde 32 veya 16 bit
(bazilari hemde 8 bit bile!) oldugu icin (hepsi bir fiyat meselesi),
bu tablolari taramak daha fazla zaman aliyor --> network performansi düsüyür.

Ve genelde IPv4 üzerinden "tunneling" yapiliyor,
yani IPv6 paketi IPv4 paketiyle (zarf) gönderiliyor,
karsi taraf da bu zarfi aciyor ve icinden nihayet IPv6 paketini cikariyor...
--> network performansi düsüyür.

IPv4 ile max. 2^32 (~ 4 milyar) IP adresi kullanilabilir.
IPv6 nin tek advantaji da burada, yani daha fazla adres kullanilabiliyor.
Ama desavantajlari avantajlarindan daha cok oldugu icin günümüzde
pek bir ise yaramiyor IPv6.
Belki 10..15 sene sonra durumlar degisebilir...

"Another aspect is that networks are currently using ipv4 as default,
so the ipv6 sites that are already in use are "translated" into a
ipv4 compatible form. This adds to the slowdown.
Many network-gurus already claimed that ipv6 is probably useless
and will never be necessary. (ipv6 was started out of fear that the
available network adresses wouldn't be sufficient for the near future).
A third aspect is that some ipv6 servers are configured badly,
causing memory leaks with websites, so that the memory size of pages
appears to be much bigger than it really is. This can cause tremendous
slowdowns and freezing networks (denial of service),
forcing a reset of the machine or the router. "
(Kaynak: http://mandrivausers.org/index.php?showtopic=27992 )


> 2008/11/27 Adem:
> >
> > IPv6 cöp tenekesine :-)
> >
> > IPv6 bir ölü dogumdur. Ona hic gerek yoktu.
> > Kimse de kullanmiyor. Hem kullaninca performansi düsürüyor.
> >
> > Sirketler birer birer private network adresleri kullanmaya
> > basladilar (mesela 192.168.x.y), cünkü bu adresler private oldugu
> > icin Internete route yapilmiyor; disardan böyle networka girmek de
> > normalde mümkün degil (routerler route yapmiyor böyle adrese).
> > Yani private IP'ler public IP'lerden daha saglam.
> > Adres kisitligi esasen hic yok. IPv4 akillica kullanilinca
> > dünya nüfusu bundan 4 kat olsa bile yeter, cünkü
> > sadece public makinalarin (Internet web server, mail server vs.)
> > public IP'si olmasina gerek var (veya public routerden private adrese
> > port forwarding...); diger makinalarin hepsi private olabilir...
> >
> > Linux'ta IPv6'yi komple disable yapmak basit:
> > http://beranger.org/index.php?article=1127&page=3k
> > http://www.debian-administration.org/articles/409
> >
> >
> > Not: gönderdigim server (news.gmane.org) Subject'te sadece ASCII kabul ediyor...



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