Yixing Real or Fake?

http://search.sothebys.com/jsps/live/lot/LotDetail.jsp?lot_id=4GVYP

MEASUREMENTS
measurements note
4 3/8 in., 11.2 cm

DESCRIPTION
of compressed globular form with a short neck, the curved spout set opposite the arched loop handle, surmounted by a domed cover with an oval finial, the reddish brown patina with a grainy texture, inscribed on the base jia chen nian da bin zhi ('made in the jia chen year by Da Bin'), old Japanese box