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