Add 127.0.0.2 as alias for lo0 on startup, place in /Library/LaunchDaemons

local.create-lo0-alias.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
    <string>local.create-lo0-alias</string>
  <key>RunAtLoad</key>
    <true/>
  <key>LaunchOnlyOnce</key>
    <true/>
  <key>UserName</key>
    <string>root</string>
  <key>ProgramArguments</key>
    <array>
      <string>/sbin/ifconfig</string>
      <string>lo0</string>
      <string>127.0.0.2</string>
      <string>alias</string>
    </array>
</dict>
</plist>