Large amount of TLS handshake errors from contiv-api-proxy

[KeithTt]

kube version: 1.8.4
contiv version: 1.1.7

# kubectl logs -f contiv-netmaster-4vzqq -n kube-system -c contiv-api-proxy

2017/12/22 17:16:25 http: TLS handshake error from 192.168.5.14:9680: EOF
2017/12/22 17:16:25 http: TLS handshake error from 192.168.5.41:22517: EOF
2017/12/22 17:16:26 http: TLS handshake error from 192.168.5.11:10923: EOF
2017/12/22 17:16:26 http: TLS handshake error from 192.168.5.71:20484: EOF
2017/12/22 17:16:26 http: TLS handshake error from 192.168.5.12:44150: EOF
2017/12/22 17:16:26 http: TLS handshake error from 192.168.5.13:58739: EOF
2017/12/22 17:16:27 http: TLS handshake error from 192.168.5.87:6584: EOF
2017/12/22 17:16:27 http: TLS handshake error from 192.168.4.49:40916: EOF
2017/12/22 17:16:27 http: TLS handshake error from 192.168.4.45:18961: EOF
2017/12/22 17:16:27 http: TLS handshake error from 192.168.5.18:41053: EOF
2017/12/22 17:16:27 http: TLS handshake error from 192.168.5.15:56849: EOF
2017/12/22 17:16:27 http: TLS handshake error from 192.168.4.46:29741: EOF
2017/12/22 17:16:28 http: TLS handshake error from 192.168.5.10:28298: EOF
2017/12/22 17:16:28 http: TLS handshake error from 192.168.3.93:8006: EOF
2017/12/22 17:16:28 http: TLS handshake error from 192.168.5.17:16853: EOF
2017/12/22 17:16:28 http: TLS handshake error from 192.168.5.19:2086: EOF
2017/12/22 17:16:28 http: TLS handshake error from 192.168.5.86:59901: EOF
2017/12/22 17:16:29 http: TLS handshake error from 192.168.5.72:28549: EOF
2017/12/22 17:16:29 http: TLS handshake error from 192.168.4.44:56343: EOF
2017/12/22 17:16:30 http: TLS handshake error from 192.168.3.95:30805: EOF
2017/12/22 17:16:30 http: TLS handshake error from 192.168.5.14:10677: EOF
2017/12/22 17:16:30 http: TLS handshake error from 192.168.5.16:62852: EOF
2017/12/22 17:16:30 http: TLS handshake error from 192.168.5.41:23309: EOF
2017/12/22 17:16:31 http: TLS handshake error from 192.168.5.11:13368: EOF
2017/12/22 17:16:31 http: TLS handshake error from 192.168.5.71:21443: EOF
2017/12/22 17:16:31 http: TLS handshake error from 192.168.5.12:45375: EOF
2017/12/22 17:16:31 http: TLS handshake error from 192.168.5.13:60619: EOF
2017/12/22 17:16:32 http: TLS handshake error from 192.168.5.87:7578: EOF
2017/12/22 17:16:32 http: TLS handshake error from 192.168.4.49:42929: EOF
2017/12/22 17:16:32 http: TLS handshake error from 192.168.4.45:20833: EOF
2017/12/22 17:16:32 http: TLS handshake error from 192.168.5.18:41742: EOF

And these IPs 192.168.x.x is existing from other servers, what happened about this?