So in BF3, the support class can lay antipersonnel mines (claymores). He can also reload himself with ammunition, providing him with a never-ending stream of claymores, if he desires. How many of them actually persist on the map? If I run around the map and lay down 20 claymores, how many of them are actually there? All 20? The last X?
You can have a maximum of 2 claymores deployed at one time.
As of the December 6th patch, claymores now survive your death.