loss of network connectivity 12.0-RC1 / re0

[Philip Homburg]

>Since installing one of the first betas of 12.0 and yesterday with RC1 I 
>notice network connectivity failures every now and then. I have to
>see if I can find the time to find a reliable trigger.

On a diffrent machine, this time with em0, starting tcpdump made IPv6 work 
again. 

Two more networking related issues:
- dhclient complains on the console about option 0x52.
- wlan0 connects to a wifi SSID that is not listed in /etc/wpa_supplicant.conf