My co-worker asked me where was the rc.local file on his Fedora 17 server because he want to add something in it. I helped him for a while, so I think it is necessary to post the way here so that we can deal with this issue as soon as possible next time.
Enable rc-local service
# systemctl enable rc-local.service
Create the rc.local file in the /etc/rc.d directory, and make sure the first line is #!/bin/sh
# cat /etc/rc.d/rc.local
route add -net 10.3.111.0 netmask 255.255.255.0 gw 172.16.100.2 dev eth1.11
Make the rc.local file executable
# chmod 700 /etc/rc.d/rc.local
Reboot the server to check if the rc.local executes.