Mac launch daemon keeps loading the firewall shell script

Question

Launch daemon worked as it should but now the problem is it keeps loading the same shell script and I can see multiple entries for the same rule. sudo ipfw list. How can this be prevented?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.apple.ipfw</string>
    <key>OnDemand</key>
    <false/>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/local/ipfw.apple.startup.sh</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
    <key>ServiceDescription</key>
    <string>Apple IPFW Filter Rules</string>
    <key>StandardErrorPath</key>
    <string>/var/log/ipfw.apple.stderr</string>
    <key>StandardOutPath</key>
    <string>/var/log/ipfw.apple.stdout</string>
    <key>UserName</key>
    <string>root</string>
</dict>

Answer 1

Use LaunchOnlyOnce key in plist file.

LaunchOnlyOnce : This optional key specifies whether the job can only be run once and only once. In other words, if the job cannot be safely respawned without a full machine reboot, then set this key to be true.