Hi,
Here's how to check startup levels and modify them:
# Check (Startup disabled on all levels)
root@nsm:~$ chkconfig --list |grep -i network
network 0: off 1: off 2: off 3: off 4: off 5: off 6: off
# Modify (Enable startup at running lebels 2,3,4,5 and 6)
root@nsm:~$ chkconfig --level 23456 network on
# Check (Startup enabled on wanted levels)
root@nsm:~$ chkconfig --list |grep -i network
network 0: off 1: off 2: on 3: on 4: on 5: on 6: on