Mavericks 10.9.2: network lost after upgrade

Symptom: network stopped working suddenly after Mavericks upgrade
History:

1. Updated Mavericks to 10.9.2 using Combo update
2. Re-installed conf. using MultiBeast 6.2.1
3. Reboot
4. Network KO
5. Repair permissions: sudo diskutil repairPermissions /
6. Reboot