A. It propagates hosts reachability without support of traffic flooding.
B. Layer 3 failures do not propagate beyond the OTV edge device.
C. It extends the spanning tree between data centers.
D. It is an open standard.
E. It constrains HSRP hello messages to each data center.
Explanation:
Reference: https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Data_Center/DCI/whitepaper/DCI3_OTV_Intro/DCI_1.html