Browser "Looking Up" Slow

My desktop, Hoover, was really sluggish. I use Pinto, the laptop more often when reading my mail, so it’s not clear when this started. I first suspected Comcast until my wife confirmed only Hoover did this. I checked DNS settings and both computers were using the same DNS servers. Some Googling picked up Slow internet (download OK but “looking up” is slow) which pointed to WebBrowsingSlowIPv6IPv4 that had instructions for disabling IPv6. It seems some NICs are broken with respect to IPv6. FWIW, mine’s a Lite-On Communications Inc LNE100TX, which, IIRC, came with my Comcast installation.

Except for the editor they use, it works in Fedora, too:

  • edit /etc/modprobe.d/blacklist
  • Add this line: blacklist ipv6
  • Reboot