So I recently installed Ubuntu 10.04 (lucid) on a new computer and I experience some serious network issues. While everything else works perfectly, there are several problems related to the internet (I think they’re all actually the same problem in fact). I am plugged directly to the wall (100mbs connection) and tests on my windows machine confirm the unusual slowness of the connection on the ubuntu machine. The problems are:
1- delay of approximately 10 seconds in accessing any web page
2- same delay when trying to ssh FROM the ubuntu machine to another one (works though). However I can ssh or use vnc TO the ubuntu machine and it's reasonnably fast
3- I can ping/traceroute (like on google.com), though it seems a bit slower than normal too.
I read this thread: https://help.ubuntu.com/community/We...ngSlowIPv6IPv4 as well as some others and it seems it may have to do with ipv6 being enabled.
I did all this:
just in case I also did:
net.ipv6.conf.all.accept_ra = 0 # added in /etc/sysctl.conf
ip6tables -I INPUT -p ipv6-icmp --icmpv6-type router-advertisement -j DROP
ip -6 r # gives no “default” line
lsmod | grep ipv6 # shows nothing
From other threads, I tried:
echo 'blacklist ipv6' | sudo tee -a '/etc/modprobe.d/blacklist.local' >/dev/null
cat /proc/sys/net/ipv6/conf/all/disable_ipv6 # gives 1
net.ipv6.conf.all.disable_ipv6=1 # in /etc/sysctl.conf
sudo sysctl –p /etc/sysctl.conf
I rebooted plenty of time and... still slow...!!! maybe a tiny tiny bit faster but it could be just in my head, besides it's still significantly slower than the windows machine (which has less impressive specs, especially less RAM).
GRUB_CMDLINE_LINUX_DEFAULT=”ipv6.disable=1 quiet splash” # from GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash” in /etc/default/grub
ip a | grep inet6 # show nothing after restart
Yet all the symptoms of the ipv6 are there: “This "slow-down" results from DNS resolution failures due to broken NAT 'routers' and other DNS resolvers which don't know how to handle the AAAA DNS query. These DNS resolvers just drop the DNS query request for the AAAA record, instead of returning the appropriate negative DNS response. Because the request is dropped, the host sending the request has to time out, thus causing a perceived slow down when connecting to new hosts. » (from above thread)
I suppose there are ways to monitor more closely what’s happening, but my knowledge in network commands is insufficient...
Anyone with any idea of what else I could do??