Defend

Defend Settlement is a Minutemen radiant quest in Fallout 4.

Quick walkthrough
While playing you are notified via on screen text that a settlement needs your help defending it. On arrival you find it under attack, after a successful defense a settler will thank you and initiate a short conversation.

Detailed walkthrough
Your settlement can come under attack from one of several different groups: Super Mutants, Ghouls, Synths, Raiders, and Gunners. Simply killing them is all you need to do.

Bugs

 * (PC) If after killing a wave of synths and with no further attacks you find the quest will not complete then open the console with "`" and select a synth then type "resurrect". After the synth dies the quest should complete.
 * (PC) If on arrival you find your settlers have killed a synth infiltrator you may also find there is no attack incoming. Open the console with "`" and type "completeallobjectives 1357db" (Or maybe 1357da)