Monday, January 15, 2007

NVIDIA drivers on Ubuntu 6.06

There's a great Installation Guide here for updating the drivers for my NVIDIA GeForce FX Go 5200 Graphics card on my HP zd7140us laptop.

Problems I had before installed the NVIDIA driver.

  • Poor graphics performance. For example, screensavers were very slow.

  • Odd horizontal lines when watching a DVD in Fullscreen.

Thanks, tseliot and the Ubuntu Document Storage Facility for posting the guide.

Monday, January 8, 2007

Slow Wireless connection. IPv6 not supported on the router.

Just recently I came across an issue which took me some time to resolve (no pun intended). The problem was that when I connected to a particular WEP enabled access point (Netopia 3347NWG-EIR), connectivity to websites was very slow (about 30 seconds) using either Firefox or Lynx on my laptop running Ubuntu 6.06. This happened for any website. However, once a page was loaded from particular domain, subsequent connections to that domain were fine until the browser was closed or ignored for a few minutes.

Appearing to be a DNS issue, I tried pinging a few different domain names and the names resolved quickly and the ping times were fine. I also tried dig and response was good.

So then I thought the problem was with WEP as I had never experienced this with non-WEP APs. I disabled WEP on the AP and couldn't connect at all. (I'm not sure why this happened. it could be related to IPv6 and will test when I get a chance). I re-enabled WEP and captured some packets which revealed the problem.

When trying to browse to a domain, Firefox was trying to resolve the AAAA (IPv6) record for the domain name. There was a request every 5 seconds, and the router would drop each of the packets. After 6 attempt, Firefox would request the A (IPv4) record, which would resolve with no problem and the page would quickly load.

So, the problem was clearly with the router dropping DNS AAAA requests. I tried to upgrade the firmware, but it's already on the latest version. The best solution to this issue is for Netopia to fix this. I've sent them an email, however, I don't want to wait.

Workaround for the "IPv6 slow down" due to incapable router.

How to disable IPv6 in FireFox

First to confirm that domain name resolution of IPv6 address is causing the slowdown you can disable IPv6 in FireFox
  1. In the address bar type "about:config"
  2. In the Filter Field type "ipv6"
  3. Click on "network.dns.disableIPv6" changing the value from "false" to "true".
Browsing should now be dramatically better.

This fixes the issue for Firefox but other applications are still vulnerable.

How to disable IPv6 for Ubuntu 6.06
  1. Create the file /etc/modprobe.d/blacklist-ipv6
  2. Editing /etc/modprobe.d/blacklist-ipv6, add the line:
    blacklist ipv6
  3. Reboot
IPv6 should now be disabled, and browsing quicker.

No word from Netopia yet. Until I hear from them, this seems like the best solution.