Disconnect Message Received from Unknown Client

The following is a sample error log when disconnect message is received from an unknown client.

[radius-ep-n0-0] 2020/11/25 10:30:02.960 radius-ep [INFO] [processor.go:157] [Radius.smf.Ipc] Process continue - 2003
[radius-ep-n0-0] 2020/11/25 10:30:02.960 radius-ep [DEBUG] [coa.go:23] [Radius.smf.AAA] [] [] [11] Coa/Disconnect Req received from udp proxy
[radius-ep-n0-0] 2020/11/25 10:30:02.960 radius-ep [DEBUG] [coa.go:43] [Radius.smf.AAA] [] [] [11] SrcIp: 209.165.201.20 SrcPort: 3799 DestIp: 209.165.201.4 DestPort: 3799
[radius-ep-n0-0] 2020/11/25 10:30:02.960 radius-ep [ERROR] [coa.go:253] [Radius.smf.Ipc] Bng Coa/Disconnect req failed - Invalid Coa Client 209.165.201.20
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[radius-ep-n0-0] LOG MESSAGES:
[radius-ep-n0-0] 2020/11/25 10:30:02.960 [TRACE] [infra.message_log.core] >>>>>>>>
[radius-ep-n0-0]
[radius-ep-n0-0] 2020/11/25 10:30:02.960 [DEBUG] [Radius.smf.AAA] Coa/Disconnect Req received from udp proxy
[radius-ep-n0-0] 2020/11/25 10:30:02.960 [DEBUG] [Radius.smf.AAA] SrcIp: 209.165.201.20 SrcPort: 3799 DestIp: 209.165.201.4 DestPort: 3799
[radius-ep-n0-0] 2020/11/25 10:30:02.960 [ERROR] [Radius.smf.AAA] Unable to process Coa/Disconnect request - Error during init of Radius Message Invalid Coa Client 209.165.201.20
[radius-ep-n0-0] 2020/11/25 10:30:02.960 [TRACE] [infra.message_log.core] <<<<<<<<
[radius-ep-n0-0]
[radius-ep-n0-0] ***********************************************