The inscription is a clan sign, Yi Ya Gao.
Compare the Shang dynasty ding of slightly larger size (20 cm. high) flat cast with a similar diamond and circle band, but with a band of pairs of birds rather than dragons below the rim, illustrated in Zhongguo Qingtongqi Quanji - Shang, vol. 2, Beijing, 1997, p. 18, no. 18.