I read this post on QUIC over at LWN. QUIC is a protocol that multiplexes network connection streams on top of UDP (to get through routers). I had no idea that it was actively used in production with YouTube! Apparently the YouTube mobile app uses QUIC for streaming videos. According to Jana Iyengar (from Google) around 35% of outbound traffic is happening using QUIC.
dhclient and resolv.conf
For some reason, when I get onto a client's network and run /sbin/dhclient on my hacked-together-linux notebook, dhclient gets an IP address via DHCP, but doesn't update my /etc/resolv.conf with the local name servers, so names don't get resolved using DNS.
I haven't figured out a fix for this yet, but a temporary work-around is to have a look at the lease in the /var/state/dhcp/dhclient.leases file. You should see a line like "option domain-name-servers 192.168.94.49;". Just put that IP address in the /etc/resolv.conf file (ie "nameserver 192.168.94.49").