OUTLINE: Disable IPv6

[mark]

I've seen lots of posts about problems with IPv6 (slow network/Internet connections, DNS resolution problems, etc.). I've also seen several posts presenting solutions to these issues. Herewith, what I had to do to disable IPv6 and get reasonable connection & DNS speeds.

1. sudo gedit /etc/modprobe.d/aliases (or your preferred text editor)
2. Find the line: alias net-pf-10 ipv6
3. Edit this to: alias net-pf-10 off
4. Save the file and reboot

Please note that many of the suggestions I've seen recommend running the command sudo update-modules before rebooting; whenever I've done this, I still see IPv6 active (i.e., the sit0 section when running ifconfig -a) and still experience the network performance problems.

Finally, with Mozilla browsers (Firefox or Suite), you can enter about:config in the address bar, locate the line starting with network.dns.disableIPv6 and change the value to true. (I'm not sure if this is necessary; I do know that, by itself, it doesn't solve the problem. But, hey - it can't hurt!)

As I said, several other folks have offered variations on this procedure - and I think I've tried 'em all. This is the method that has worked reliably, for me, through the course of several complete reinstalls.

12/15/04 - My last reinstall, this didn't work - what did work was:

3. Edit this to: alias net-pf-10 off ipv6

Not sure what changed, but there it is...

Mark

[Old Pink]

This deserves a BUMP, as it's a really helpful thread.

Additional: Disabling ipv6 in Firefox

1. Type about:config in your address entry bar (in firefox)
2. Type "ipv6" in the filter
3. Change the value of "network.dns.disableIPv6" to true

[phormion]

One important thing to note would be that you should only take these steps if you don't have any IPv6 connectivity. I know most people don't, but still, you never know who's reading this.

Also, there's a pretty good description of the network.dns.disableIPv6 option on MozillaZine: http://kb.mozillazine.org/Network.dns.disableIPv6. Basically, if it's not set to true, one extra query is made for each address (that's not in the browser's cache). I don't know why this isn't off by default.

[Ublis]

<snip>
2. Find the line: alias net-pf-10 ipv6
3. Edit this to: alias net-pf-10 off
4. Save the file and reboot
<snip>

This worked for me - browsing is now at normal speed again. It even fixed the problem that after startup, I had to manually run "ifdown -a" followed by "ifup -a" to get the network running (simply disabling/enabling in the GUI tool didn't work, unlike in Dapper).

[wert613]

thanks this helped speed up my network greatly!

[Quintin Riis]

Reboot? wtf?

[mux2000]

Tried this and it didn't work, Connection still very slow (~3000ms ping to google), and it disconnects every 15-45 minutes as well (though for a few minutes right after reconnecting the speed is good, and then it slows down).

[findik1]

yes it worked for me

[lupin492]

Tried this and it didn't work, Connection still very slow (~3000ms ping to google), and it disconnects every 15-45 minutes as well (though for a few minutes right after reconnecting the speed is good, and then it slows down).

MUX2000: You have a poor Internet connection, not DNS problems. When you issue a ping, and the NAME of the site takes long to be related to its address, that's a DNS problem (that may also be due to a poor connectivity). But if ping tells you 3000ms, better change your ISP !
Regards.

[nautilus]

** this no longer provides any improvements to performance on feisty fawn due to patched/updated GNU LibC (see Launchpad) **

in short, please, stop doing it as the first solution to everything. it will not fix a broken dialup connection, a bad pppoe situation, or high-latency ping times to google or any other hosts.

this will only fix a possible delay in resolving AAAA records for hosts on archaic routers and other non-standards-compliant hardware (such as cheap routers) which cannot understand the request and, to our dismay, simply refuse to dignify it with any sort of response.

this causes the nslookup on your ubuntu system to eventually timeout, and try the simpler "A" record search.

--

if you disable IPv6, you will need to re-enable it for your system to operate properly on Internet2 in the future. if you do NOT have IPv6 support on your system, your system is not compliant with current Internet standards.

i hope this clears some things up. disabling ipv6 is NOT a panacea of any kind for all network issues. if anything, it's more like amputation. stop butchering your system! >:O