Yes EX3400 (along with EX2300, EX4300, EX4600, and EX9200) are all ELS based hardware platforms. EX3400 is missing IP Source Guard. This feature is supposed to be added into this product in either 17.3 or 17.4 I believe.
This why you can not config IPSG on EX3400 with any current code available. There have been other threads in this forum covering this.