How-To: Disable IPV6 to speed up Internet.

[Tom Mann]

Thanks, ipv6 doesn't like certain D-Link hardware, including my router
This little nugget solved the lot!

[cookfromfrozen]

Is there any way when disabling IPv6 through this guide to apply the changes without rebooting?

I've tried

sudo /etc/init.d/networking restart

and I've ifdown and ifup'd the interface but it seems the only way is to reboot. Come on, this is Linux

[Psquared]

After fiddling with this for sometime, I finally did the Dapper thing and no more ipv6. Pages refresh faster in Firefox without any timeouts or having to hit stop and click again and again. This is a great help, but don't forget to reboot and use the Dapper instructions if you have 6.06.

[hype]

There's an easy way: instead of changing aliases file, create fie named bad_list in /etc/modprobe.d containing this line:

alias net-pf-10 off

Now reboot and voila, no IPv6 on your system!

This method will work even if /etc/modprobe.d/aliases get replaced at some update.

Hi mhael,
i've just added

alias net-pf-10 off

in /etc/modprobe.d/bad_list .

After reboot, i made a ip a | grep inet6 , but it still outputs:

~$ ip a | grep inet6
    inet6 ::1/128 scope host
    inet6 fe80::201:6cff:fe3d:6208/64 scope link
    inet6 fe80::250:56ff:fec0:8/64 scope link
    inet6 fe80::250:56ff:fec0:1/64 scope link

This means ipv6 Hasn't been disabled, right?

Did any one tested both methods? Is it a problem of "bad_list" not being loaded by modprobe or something?

EDIT: Modifying my "blacklist" in modprobe.d just did the trick !

[peter b]

hello to all

today I downloaded just for the fun of it Kubuntu for amd 64 -that's right, the one with K! and to make a long story short, on the same PC it booted live flawlessly, autodetected and configured RIGHT OFF THE BAT the router, the NIC and in no time I was surfing the net, sending and receiving e-mail AT FULL BROADBAND SPEED WITH ipv6 enabled. So I'll leave it up to the readers to draw their own conclusions re ipv6 problems expressed on this thread.
peter b

[zachofalltrades]

with all due respect to the network engineers,

Telling people that they should deal with their problem by filing bug reports with various specific application developers is not a really useful solution for most end-users. It may be true that IP6 should not be a problem for most users, but clearly it is. End users don't really care whether this is the 'fault' of their ISP, their own network equipment, their oeprating system, or their specific internet application. How something 'should' work isn't really important to most users -- people really only care about the result (the symptom, not the underlying cause).

guysmiley 'wrote in crayons' the solution suggested by mhael:
1. Open a Terminal Window
2. Type sudo gedit /etc/modprobe.d/bad_list/
3. In the gedit window, type: alias net-pf-10 off
4. Save the file and reboot.

For folks who just want to use their system rather than mess around with the internals. This is a silver bullet. It bypasses the need for the end user to tweak specific applications. It 'fixes' the problem at the system level. By creating a new file instead of editing one that already exists, they avoid messing something up, or losing their tweak by some other upgrade or automated installer. By the time most people actually need IP6, the misbehaving applications will probably be fixed, and then people can just delete this little file -- if they are even still using their current system.

BTW -- this solution 'fixed' FireFox and Evolution for me -- I was desperate until I found this thread.

[cookfromfrozen]

In my experience you need to do all three methods (the aliases file, the bad_list file AND the blacklist file) to fully disable IPv6. I've tried just the bad_list trick or the blacklist trick on its own and I still get output from ip a | grep inet6.

If you get any output from that command then IPv6 is still enabled so you'll probably need to do all three "hacks" to finally turn it off.

Or...just buy a router that doesn't freak out with IPv6.

[missmoondog]

From the ubuntu-devel mailing list (culled from a variety of posts)
Originally Posted by ubuntu-devel list
Having IPv6 be the cause of 'slow' connection is actually a common
misconception, reinforced in that disabling some IPv6 features may help
mitigate the problem, in most cases it is the result of bad network
configuration.

IPv6 itself does not in any way slow down your connection, problems will
arise however if you have a route out to the IPv6 internet but it is not
operational, as the browser will try to connect and it will take a while
to time-out, note this would also happen with a bad IPv4 internet
connection.

Another cause in the past has been bugs in programs (e.g. mozilla) that
do the wrong thing internally, most of the major problems here have been
fixed.

As above, these issues would *only* happen if the website you are trying
to connect to has an IPv6 address associated. Another cause can be
having an IPv6 name-server configured in resolv.conf or similar, in
which case the problem would arise if you were trying to connect to
*any* address.


Most people do not have a problem with having IPv6 enabled, it
simply is un-used when not in use.

If you are having problems, it is likely due to some kind of
misconfiguration, you would need to diagnose that.

In particular, the commands 'ip -6 route' may help, it will indicate if
you have any routes to the broader IPv6 world (look for '2000::/3' and
'default' routes). THis may be caused by an incorrect router on your
network, or by using tunneling software (such as tspc from
freenet6.net), or a number of other reasons.

In simpler terms: with a default Ubuntu install, if you're not using
IPv6, you shouldn't even know it's there. If you're experiencing
negative side effects, they're likely the result of a broken application
or incorrect configuration. Firefox, for instance, is a known culprit.

One thing you can try is, with IPv6 enabled, to launch a terminal, and
type 'host www.google.com'. If the command succeeds quickly, listing
Google's IPs, then you're not having general network connectivity
trouble, and you can start filing bug reports against whichever specific
applications are being slow.


My suggestion to all those with "slow" internet. Try the last paragraph especially, then start filling bug reports.

yep, couldn't agree more. ipv6 has nothing to do with your normal connection. just disabling it in your browser is sufficient.

[Buelldozer]

With all due respect to yagisan and missmoondog. In my opinion you ask too much.

Which do you suspect *most* users would rather do when faced with an IP based problem?

1) Issue a single command to the operating system to disable a feature that they do not use or need but is causing major system slowdowns.

2) Spend hours troubleshooting networking hardware that may or may not be having problems with this 'newfangled' IP addressing scheme and then replacing said hardware (that costs money) IF they can track that as the source of their ills. If, or probably then, when they continue to have issues spend time documenting which applications are having problems and filing bug reports using 20 different tracking systems, each with it's own logon and password set and different operating scheme. Then they get told "It's a problem with your hardware or distro" by some cranky developer.

What you see in this thread is "most" users. The harcore techs are filing bug reports and chasing hardware. For the non-technical user it is perfectly acceptable to JUST TURN OFF IPV6!

Remeber, most users couldn't figure out IPV*4* if they had a CCIE right there helping them, you can forget IPV6. (K)Ubuntu puts itself out there as a distribution for new Linux users and you can't, and shouldn't, expect them to spend hours and dollars sorting out crazy routing issues.

Perhaps those issues are the fault of their hardware, perhaps they are the fault of their software, but either way they do not have the technical knowledge or skill to solve the problem on their own.

These users post to these forums for help from other, and hopefully more knowledgeable, users. They don't post here to be told that they need to spend hours and dollars chasing ghosts in the hardware and glitches in the applications.

Again, in my opinion, unless you're willing to handhold them through testing hardware and filing bug reports with all of their software vendors you should simply tell them to turn off the source of their problems.

With all due respect, please remember that you are working, mostly, with people that have little experience in network and application troubleshooting.

[Ted_Smith]

In Dapper I got to disable ipv6 in this way: Make a file called 'blacklist-ipv6' in /etc/modprobe.d/ and inside the file put this text: blacklist ipv6

So the next time you boot, the ipv6 module won't be loaded (lsmod | grep ipv6 ; it's a better way to check ipv6 presence than 'ip a | grep inet6', I think, since the module manages the thing).

Was the only one out of the three methods that worked for me. Thanks! The other two made no difference in my case.

And yes, FF does seem much faster!

Ted