I got this result from your commands, more details in the next comment with journalctl lines relevant to this:

sudo systemctl status  network-pre.target networking.service network.target <email address hidden>
● network-pre.target - Network (Pre)
   Loaded: loaded (/lib/systemd/system/network-pre.target; static; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:systemd.special(7)
           http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget

● networking.service - LSB: Raise network interfaces.
   Loaded: loaded (/etc/init.d/networking)
  Drop-In: /run/systemd/generator/networking.service.d
           └─50-insserv.conf-$network.conf
        /lib/systemd/system/networking.service.d
           └─network-pre.conf
   Active: active (exited) since Wed 2015-02-11 13:26:25 EST; 55s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 1214 ExecStart=/etc/init.d/networking start (code=exited, status=0/SUCCESS)

Feb 11 13:26:25 ubuntu networking[1214]: * Configuring network interfaces...
Feb 11 13:26:25 ubuntu networking[1214]: /etc/resolvconf/update.d/libc: Warn...f
Feb 11 13:26:25 ubuntu networking[1214]: ...done.

● network.target - Network
   Loaded: loaded (/lib/systemd/system/network.target; static; vendor preset: enabled)
   Active: active since Wed 2015-02-11 13:26:26 EST; 54s ago
     Docs: man:systemd.special(7)
           http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget

● <email address hidden> - ifup for eth0
   Loaded: loaded (/lib/systemd/system/ifup@.service; static; vendor preset: enabled)
   Active: inactive (dead)

Feb 11 13:27:21 ubuntu systemd[1]: [/lib/systemd/system/ifup@.service:14] T...g.
Hint: Some lines were ellipsized, use -l to show in full.
luke@ubuntu:~$ sudo systemctl status -l  network-pre.target networking.service network.target <email address hidden>
● network-pre.target - Network (Pre)
   Loaded: loaded (/lib/systemd/system/network-pre.target; static; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:systemd.special(7)
           http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget

● networking.service - LSB: Raise network interfaces.
   Loaded: loaded (/etc/init.d/networking)
  Drop-In: /run/systemd/generator/networking.service.d
           └─50-insserv.conf-$network.conf
        /lib/systemd/system/networking.service.d
           └─network-pre.conf
   Active: active (exited) since Wed 2015-02-11 13:26:25 EST; 1min 35s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 1214 ExecStart=/etc/init.d/networking start (code=exited, status=0/SUCCESS)

Feb 11 13:26:25 ubuntu networking[1214]: * Configuring network interfaces...
Feb 11 13:26:25 ubuntu networking[1214]: /etc/resolvconf/update.d/libc: Warning: /etc/resolv.conf is not a symbolic link to /run/resolvconf/resolv.conf
Feb 11 13:26:25 ubuntu networking[1214]: ...done.

● network.target - Network
   Loaded: loaded (/lib/systemd/system/network.target; static; vendor preset: enabled)
   Active: active since Wed 2015-02-11 13:26:26 EST; 1min 35s ago
     Docs: man:systemd.special(7)
           http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget

● <email address hidden> - ifup for eth0
   Loaded: loaded (/lib/systemd/system/ifup@.service; static; vendor preset: enabled)
   Active: inactive (dead)

Feb 11 13:27:21 ubuntu systemd[1]: [/lib/systemd/system/ifup@.service:14] Trailing garbage, ignoring.
Feb 11 13:28:01 ubuntu systemd[1]: [/lib/systemd/system/ifup@.service:14] Trailing garbage, ignoring.
luke@ubuntu:~$ sudo systemctl status   network-pre.target networking.service network.target <email address hidden>
● network-pre.target - Network (Pre)
   Loaded: loaded (/lib/systemd/system/network-pre.target; static; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:systemd.special(7)
           http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget

● networking.service - LSB: Raise network interfaces.
   Loaded: loaded (/etc/init.d/networking)
  Drop-In: /run/systemd/generator/networking.service.d
           └─50-insserv.conf-$network.conf
        /lib/systemd/system/networking.service.d
           └─network-pre.conf
   Active: active (exited) since Wed 2015-02-11 13:26:25 EST; 1min 47s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 1214 ExecStart=/etc/init.d/networking start (code=exited, status=0/SUCCESS)

Feb 11 13:26:25 ubuntu networking[1214]: * Configuring network interfaces...
Feb 11 13:26:25 ubuntu networking[1214]: /etc/resolvconf/update.d/libc: Warning: /etc/res...onf
Feb 11 13:26:25 ubuntu networking[1214]: ...done.

● network.target - Network
   Loaded: loaded (/lib/systemd/system/network.target; static; vendor preset: enabled)
   Active: active since Wed 2015-02-11 13:26:26 EST; 1min 46s ago
     Docs: man:systemd.special(7)
           http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget

● <email address hidden> - ifup for eth0
   Loaded: loaded (/lib/systemd/system/ifup@.service; static; vendor preset: enabled)
   Active: inactive (dead)

Feb 11 13:27:21 ubuntu systemd[1]: [/lib/systemd/system/ifup@.service:14] Trailing garbag...ng.
Feb 11 13:28:01 ubuntu systemd[1]: [/lib/systemd/system/ifup@.service:14] Trailing garbag...ng.
Feb 11 13:28:13 ubuntu systemd[1]: [/lib/systemd/system/ifup@.service:14] Trailing garbag...ng.
Hint: Some lines were ellipsized, use -l to show in full.