tor.service fails to start on system boot if network is not initialized at the moment.

# systemctl status tor
tor.service - Anonymizing Overlay Network
Loaded: loaded (/usr/lib/systemd/system/tor.service; enabled)
Active: failed (Result: exit-code) since Tue, 2012-10-30 21:58:09 MSK; 36min ago
Process: 323 ExecStart=/usr/bin/tor -f $TOR_CONF $TOR_ARGS (code=exited, status=1/FAILURE)
CGroup: name=systemd:/system/tor.service

Oct 30 21:58:27 oak.local tor[323]: Oct 30 21:58:08.734 [notice] Tor v0.2.2.39 (git-bec76476efb71549). This is experimental software. Do not rely on it for strong anonymity. (Running on Linux x86_64)
Oct 30 21:58:27 oak.local tor[323]: Oct 30 21:58:08.807 [warn] Skipping obsolete configuration option 'Group'
Oct 30 21:58:27 oak.local tor[323]: Oct 30 21:58:08.836 [notice] Initialized libevent version 2.0.20-stable using method epoll. Good.
Oct 30 21:58:27 oak.local tor[323]: Oct 30 21:58:08.836 [notice] Opening Socks listener on 192.168.0.10:9050
Oct 30 21:58:27 oak.local tor[323]: Oct 30 21:58:08.836 [warn] Could not bind to 192.168.0.10:9050: Cannot assign requested address
Oct 30 21:58:27 oak.local tor[323]: Oct 30 21:58:08.836 [warn] Failed to parse/validate config: Failed to bind one of the listener ports.
Oct 30 21:58:27 oak.local tor[323]: Oct 30 21:58:08.836 [err] Reading config failed--see warnings above.

Proposed solution is to add network dependency to the tor.service [Unit] section:

After=network.target