Arch Linux

pedepy

Member

Registered: 2007-02-21

Posts: 198

ipv6 won't go away

i need to disable ipv6 to properly use tethering via pdanet on my iphone, otherwise dns lookups can take several seconds (sometimes, up to 20....) ...

disabling ipv6 inside applications such as firefox solves the problem, so I now want to disable it system wide, but I cant seem to find how. adding the 'alias net-pf-10 off' line in modprobe.d/modprobe.conf does nothing. the module 'ipv6' is always loaded to memory and i can't just rmmod it without removing a cascade of modules before it ... and blacklisting it in rc.conf is also not working.

any thoughts?

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deej

Member

Registered: 2008-02-08

Posts: 395

Re: ipv6 won't go away

Strange, 'alias net-pf-10 off' does the deed on my box. Are there any messages in the /var/log/ files
which could point to a problem ? Does 'dmesg' give any clues ?

Deej

harpo

Member

Registered: 2009-05-14

Posts: 21

Re: ipv6 won't go away

i need to disable ipv6 to properly use tethering via pdanet on my iphone, otherwise dns lookups can take several seconds (sometimes, up to 20....) ...

disabling ipv6 inside applications such as firefox solves the problem, so I now want to disable it system wide, but I cant seem to find how. adding the 'alias net-pf-10 off' line in modprobe.d/modprobe.conf does nothing. the module 'ipv6' is always loaded to memory and i can't just rmmod it without removing a cascade of modules before it ... and blacklisting it in rc.conf is also not working.

any thoughts?

You may have the same glibc 2.10 problem as me.

Try this in /etc/resolv.conf:

options single-request

pedepy

Member

Registered: 2007-02-21

Posts: 198

Re: ipv6 won't go away

yea 'options single-request' does appear, at first glance anyway, to speed things up ... I assume that this gets applications to 'give up' on ipv6 quicker than they normally would ?

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chupocabra ... psupsuspsu psu psu

harpo

Member

Registered: 2009-05-14

Posts: 21

Re: ipv6 won't go away

yea 'options single-request' does appear, at first glance anyway, to speed things up ... I assume that this gets applications to 'give up' on ipv6 quicker than they normally would ?

Not quite. Since glibc 2.10 the NSS resolver library attempts to parallelize requests to nameservers for IPv4 and IPv6 addresses. This should be faster in most cases. However, some broken DNS servers can't handle this, mostly those found on home router gear. Additionally, I am seeing a problem with stateful packet inspection on some Cisco routers (often doing NAT), which is causing the second response from the server to fail.

In this situation (getting less than two responses) the NSS library implements a timeout (I see about 5 sec), before resending the requests, serially this time. It is this timeout that you are seeing.

Another workaround is to run some kind of DNS caching locally, e.g. with dnsmasq or nscd.

pedepy

Member

Registered: 2007-02-21

Posts: 198

Re: ipv6 won't go away

well ... adding single-request to resolv.conf does not do it after all .... in fact, it even causes firefox (in which I have disabled ipv6), to slow down look ups quite a bit !!.....

maybe ive wrote it down wrong, but i dont think so .. i just added 'options single-request' followed by a blank line, before nameservers, and well thats it ...
asdfsafd
in either case, im thinking maybe my iphone just can't use ipv6 requests and disabling it system wide while tethering would still be a better option ..... so doesnt anyone know why none of the documented methods work for me ??.........

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chupocabra ... psupsuspsu psu psu

arch0r

Member

From: From the Chron-o-John

Registered: 2008-05-13

Posts: 597

Re: ipv6 won't go away

blacklist ipv6 in /etc/modprobe.d/modprobe.conf ?

.:B:.

Forum Fellow

Registered: 2006-11-26

Posts: 5,819

Website

Re: ipv6 won't go away

You did as the wiki suggested?

http://wiki.archlinux.org/index.php/IPv … the_Module

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R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: ipv6 won't go away

If adding the alias in modprobe.conf didn't work then I guess something else is loading the module for you, the alias just prevents it to autoload during startup (it works fine here), if anything else tries to load it will load. As for it still loading even when blacklisted ... no idea, what did you blacklist, net-pf-10 or ipv6?

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R00KIE
Tm90aGluZyB0byBzZWUgaGVyZSwgbW92ZSBhbG9uZy4K

arkham

Member

From: Stockholm

Registered: 2008-10-26

Posts: 516

Website

Re: ipv6 won't go away

Try also adding !ipv6 to your MODULES() array in rc.conf

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