On Wed, 2004-04-21 at 15:00, Jeff Pitman wrote: > Hi all: > > The following is just a "word of warning" about IPv6 causing initial > connect slowness in Kernel 2.6. Target audience: packagers of kernel > 2.6 in Fedora Core 2 (maybe provide a work around or configurable shut > off mechanism) or any kernel hackers or someone with additional > familiarity. I'm writing this purely out of my personal experience and > hope that it might be helpful for those on this list. > > Without disabling IPv6 in /etc/modprobe.conf with "alias net-pf-10 off", > in certain environments that evidently do not support "it"--"it" being > quite a nebulous definition since I am far from understanding any piece > of IPv6--initial network connections will be obnoxiously slow, both DNS > lookups and simple "telnet www.google.com 80" tests. With ipv6 enabled, the libc resolver will afaik try to resolve hostnames as ipv6 addresses first. For alot of reasons that might take a long time.. (one example is me having a local dns server used for internal hosts on a network not always on the internet, and havinf "forward" hosts in named.conf... ipv6 dns lookups takes a damn long time to timeout when not connected to the internet.) So perhaps there should be(and maybe there is..) a way to say try ipv4 first in /etc/resolv.conf ?
