+ @param eid_set - if non-zero request info about specific mapping
+ @param vni - virtual network instance; valid only if eid_set != 0
+ @param prefix_length - prefix length if EID is IP address;
+ valid only if eid_set != 0
+ @param eid_type - EID type; valid only if eid_set != 0
+ Supported values:
+ 0: EID is IPv4
+ 1: EID is IPv6
+ 2: EID is ethernet address
+ @param eid - endpoint identifier