How to find out what duplex my router is?

How do I find this out? Router is NetGear WNDR3700 actually WNDR37AV, but I don’t think they are any different. One just has Ready Share.
Answer #1
full duplex.
Answer #2
Is it 1000 Base T?
Answer #3
Five (5) 10/100 (1 WAN and 4 LAN) Gigabit Ethernet ports with auto-sensing technology

I believe it is because the router is up to Gigabit.