Upgrading Gentoo using Emerge

A few days ago, for whatever reason, I had the insane urge to upgrade all the software on my Gentoo system to the latest version. I still havent gotten around to compiling the latest kernel that came with the update (2.6.33), mostly because I've forgotton what what hardware I have and I haven't been having any problems with my current kernel (2.6.31).
Things actually went smoothly for the most part, the process only got hung up on compiling and installing Virtual Box. I figured I wouldn't mess around with it because I'm running a Windows XP virtual machine for work and I don't want to screw that up.

I started with syncing emerge:

sudo emerge --sync

and then started the update:

sudo emerge -av --update world --deep

After confirming the upgrade, I let it compile overnight. Unfortunately, I didn't use the "--keep-going" option so the job stopped when it had problems with Virtual Box. I used the "--skip-first" option to successfully complete the rest.

So once that was all finished, I ran etc-update, and crap! 31 config files need to be updated! Mind numbing...
I got to work merging the files that I knew had custom changes in them. After a while, the -3 option was looking really tempting (auto-merge files with new copy). I finally gave in and used it with about 15 files left, and woohoo! Mundane file editing over!

Everything seemed great until I rebooted and I had no internet. Some quick troubleshooting revealed that I was receiving a dhcp address, but no DNS servers, meaning I was able to ping internet IP addresses, but not their names.

A nice little side effect of not being able to resolve names is my time was off, because my ntp client couldn't resolve pool.ntp.org. A temporary fix is really easy, just open up /etc/resolv.conf and add some name servers.

sudo nano /etc/resolv.conf

Then add:

nameserver 208.67.220.220

(OpenDNS)

Once done, I was immediately able to browse the web and sync my time, but why did it happen in the first place? To add to the confusion, every time I reboot the computer, dhcp overwrites the resolv.conf file with a blank file, meaning I have to add the DNS again!
Well, it turns out to be my mistake. I took a look at /etc/conf.d/net and noticed that I had set up the machine for a static IP, but dhcp was also starting at boot, overwriting the file. I'm actually not too sure how it was working before the update, but to fix it I just ended up setting it to full dhcp. After setting that, I rebooted and presto! Internet with no tweaks!