Hello everyone. I been having this random dns problem, in Ubuntu 10.04 and in 10.10 it started about 2 weeks ago after (I believe) an update. Basically when I go to a website randomly I get that the website I'm visiting is not available ("Oops! Google Chrome could not connect to ..." & "This webpage is not available."). I tested with Chromium "7.0.515.0 (58587)" and Firefox minefield (4.0ish) and 3.6.9. I did these 4 things already: /etc/default/grub GRUB_CMDLINE_LINUX="ipv6.disable=1" and this: /etc/sysctl.conf net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1 *disabling Chromium DNS pre-fetching *using Google and OpenDNS servers as well as ISP DNS servers. But didn't improve, also no other computers in my network have the same problem. All computer wired to the same router. I'm a software engineer that run out of ideas, please help me. Thanks in advance. UPDATE: some programs (synaptic / firefox update/ vuze(azureus)) say connection refused for the error. Most of the time a second try will fix the "refusal". UPDATE2: I found out with Wireshark, that everytime I have this problem i've got this 192.168.0.10 8.8.8.8 ICMP Destination unreachable (Port unreachable) Confirmed an ISP error. ISP;Speedy Location: Argentina, Buenos Aires (capital Federal) Area.