Upgraded Linux Version (Debian, Ubuntu) – How to fix slow internet
The directions below are a bit outdated with the latest version of Ubuntu. You can still disable IPv6 in Firefox per the instructions below, but if you’re on Ubuntu (or any variety of Ubuntu), there is no longer the alias file.
Instead, use sysctl to disable IPv6 without rebooting by typing this in Terminal (you may need to enter your password):
sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1
To disable permanently add
net.ipv6.conf.all.disable_ipv6=1
to /etc/sysctl.conf.
[ Got this tip from Andreas N in the comments of this article: http://www.ubuntugeek.com/how-to-disable-ipv6-in-ubuntu.html ]
I noticed a substantial slowdown of my internet, particularly in IceWeasel aka Firefox for Debian. After investigating a bit, I found that IPv6 was turned on! Oy! I don’t need IPv6 and I sure don’t need it hogging all my bandwidth.
Make a backup of the alias file by opening terminal in super user mode, I just used the icon already on Debian, under Applications | System Tools | Terminal Server – Super User Mode:
cp /etc/modprobe.d/aliases /etc/modprobe.d/aliases.backup
Now, lets open it for editing. Since your in Super User mode (you are right!?), you will be able to save this file after making these changes.
Open aliases by entering:
nano /etc/modprobe.d/aliases
Find this line:
alias net-pf-10 ipv6
Replace it with these three lines:
alias net-pf-10 ipv6 off
alias net-pf-10 off
alias ivp6 off
Now, save the file by pressing CTRL-X and saying Yes to save the changes.
Close out of Terminal Mode.
While we’re at it, let’s tweak IceWeasel to not use IPv6 as a default.
From within IceWeasel, open a new tab window. Type the following in the address/location bar:
about:config
You’ll get a funny message about being sure you know what you’re doing. Of course you do, click OK/Yes.
Search/Sort/Filter for the following by starting to type it:
network.dns.disableIPv6
Double-click (toggle) it to set it to true
Close IceWeasel and Reboot your entire system. To see if you’ve really turned off IPv6, open Terminal and enter this command:
ip a | grep inet6
If some lines are displayed, IPv6 is still on. If nothing is returned, IPv6 is off. Happy fast surfing!
I guess you found this on the Debian Forums?
http://forums.debian.net/viewtopic.php?p=196435
Not that thread actually, but thanks for the link. I compilied my post from several threads including this one: http://forums.debian.net/viewtopic.php?p=49686 and this one http://www.fak3r.com/2008/12/02/howto-disable-ipv6-networking-in-debian/ and combined them in this one walk thru, which is the only way I got it to work on my system. None of those threads worked independantly, so I combined the steps here.
Okay
I tried googling for it as well, but didn’t find those threads. Btw. you are the first hit on Google now, if one types “slow internet in lenny”.
Ha! I had no idea! I must have googled for 3 days after I upgraded, and I upgraded when it was still in “testing” and even then, with the posts I found it was trial and error to get back my speedy internet. Did you get yours fixed? What worked? I’m interested to know if you had to do the same combination of turning off ipV6 and the IceWeasel tweak. Let me know and thanks for your posts!
Initially I used the second hit on Google (http://forums.debian.net/viewtopic.php?p=197399&sid=6445dbfe3b0c6458f02e06d052e9bc8e) to get Lenny flying.
But for some reason I reinstalled, and when I tried to find that particular post, your blog suddenly appeared.
Thanks Nancy.
I also added IPV6 to the black list to get it turned off all the way by adding “blacklist ipv6″ to the end of etc/modprobe/blacklist as suggested here.
http://forums.debian.net/viewtopic.php?p=197399&sid=6445dbfe3b0c6458f02e06d052e9bc8e
I was suprised to find my new debian hooking up to the net automatically.
For years I always had to mess around to get it to go.
Wonder what other treats I am in store for?
Thanks for the help!
j