Browsing secure sites (https) is very slow.


I’ve recently installed openSUSE 11.4 (64 bit) on my system and am experiencing severe performance issues with websites using https (any site using https). Page loads over https take anywhere between 30 seconds to 2 minutes. It’s the same issue posted here Secure sites load slow or not at all – there was no confirmed solution.

  • My router/hardware configuration has not changed in a long time and I’ve run Ubuntu, Arch Linux, and Windows XP on the same machine within the last year and have not had any issues.

  • I also have a laptop running Arch Linux (kernel 2.6.38) and this problem does not occur using Firefox 4 or Chrome. To add to the madness this problem occurs while running Firefox 4 inside a Windows 7 guest via virtual box, but NOT while running IE 8 inside the same guest.

  • This issue occurs using Firefox 4, Chromium, Opera, Konqueror, and Arora.

  • I’ve disabled ipv6 in Firefox via about:config.

  • I’ve disabled ipv6 in yast and have attempted to use both the “ifup” and “networkmanager” options.

  • I am not using a proxy server.

  • I’ve attempted the fix posted in the Ubuntu forums for a similar problem [ubuntu] [SOLVED] Banking Site is very slow - Ubuntu Forums]( to no avail, i.e.,

# as root
echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
# append to /etc/sysctl.conf
net.ipv4.tcp_window_scaling = 0

  • SSH and retrieving mail via IMAP + SSL does not appear to be affected.

  • Download speeds and regular page loads are not affected.

Any ideas?

Also, the issue does not occur if I use my work VPN.

That suggests that the problem might be with your ISP, and not with your computer.


OK, I was mistaken, the problem is NOT happening in Konqueror or Arora (I was confusing myself with another issue I have with Facebook).

After playing around with Firefox, Chromium, and Konqueror for the last little while, this is what is

Firefox / Chromium

  • after starting the browser all https page loads are slow
  • after attempting to load an https page a few times it eventually loads quickly
  • after the spontaneous quick page load, all https page loads are quick for about a minute
  • after a minute all https page loads are slow again
  • using VPN fixes the problem

Konqueror / Arora

  • no issues

I have been testing by doing the following:

Start Konq., go to - success, go to banking site - success
Start Firefox, go to - slow, go to banking site - slow
Start Chromium, go to - slow, go to banking site - slow
Close all browsers

Start VPN
Ping to ensure connection is up
Start Konq., go to - success, go to banking site - success
Start Firefox, go to - success, go to banking site - success
Start Chromium, go to - success, go to banking site - success
Close all browsers
Disconnect from VPN

Where slow is 30 seconds to > 1 minute.
I should also note that my VPN (using VPNC) doesn’t always seem to work (i.e., NetworkManager says I’m connected but I can’t ping anything), although this does occur on my other Linux machine (laptop) as well (and when not at home).

Could this still be an ISP issue if it works for some browsers but not others?
This is just really weird.

You have DNS issues in the no VPN configuration.

Maybe Firefox and Chromium cache DNS results differently than Konqueror?

But I don’t see how changing between http and https is related to doing name resolution, I can browse to http://facebook (dot) com and it’s “instant”, but https://facebook (dot) com is very slow for instance.

And if I do:
lsof | grep firefox | grep TCP
When connected in http I see the same domains as when I’m connected in https.

Am I missing something here?

https requires reverse mapping of IP addresses to guard against spoofing.

I wouldn’t trust konqueror to do everything correctly. It has quite a few quirks.

Ah, that’s something I didn’t know.

OK, so I tried doing:
$ host some IP ]
and it is “instant”, I don’t know if that’s indicative of anything though, I don’t have much knowledge of these networking issues as you can probably tell.

I guess I should just call my ISP at this point.