I have fedora 16. All is well. So this morning, after reading my tcpdump, I decided to disable ipv6 by adding:
/etc/sysctl.conf: net.ipv6.conf.all.disable_ipv6 = 1
Sure enough, ipv6's traffic went away, and my eth0 and lo are no longer configured for inet6. Then my sound went away. I didn't want to believe it! So, I enabled/disabled it a couple more times. The result is the same--no ipv6 meant no sound.
Then I thought, how about disabling just eth0, and keep lo:
/etc/sysctl.conf:net.ipv6.conf.eth0.disable_ipv6 = 1
The sound came back.
Is there any relationship between ipv6 and sound?