In general TDES with three different keys (3-key TDES) has a key length of
168 bits: three 56-bit DES keys (with parity bits 3-key TDES has the total
storage length of 192 bits).

We are using Windows Server 2003 R2 SP2.
Is the IPSec 3DES on the Server, 2-key mode or 3-key mode?
Can you suggest MS Site or Doc written about this?