Same network device gets discovered multiple times in scom

Hi All,

In SCOM 2012 , Same network device gets discovered multiple times.

For example, if we have an ip address 10.91.180.43 added to Network discovery rule.

When Discovery is run few times.

its gets discovered multiple times and shows 3 or 4 times under Network Devices.

Please help me to fix this issue.

Thank you

Siva