perfect forward secrecy

DHE in and of itself provides PFS. If you do the following at the command line:

tmm --clientciphers 'DHE'

you'll see a bunch of DHE cipher suites from the NATIVE stack. Some of these are for SSLv3 and use DES, so probably best to trim that list a bit. It's also highly recommended these days to switch to ECDHE (also PFS). BIG-IP doesn't support DHE beyond 1024 bits, and even if it did you'd find more clients that support ECDHE than DHE with 2048, plus DHE 2048 is computationally expensive compared to elliptic curve.