Junos OS

I have given Public IP 209.249.232.130 to a member and he configured this in the firewall but in the arp I see this member's MAC: 6c:8b:d3:40:c2:60 using up the whole subnet. Do you think the issue here is from member side or on my srx. What can be done here if I am getting the below log messages? Thanks

I am getting below log messages. 

Sep 14 06:21:36  den06-core kernel: %KERN-6-KERN_ARP_ADDR_CHANGE: arp info overwritten for 209.249.232.133 from e4:38:83:84:6a:76 to 6c:8b:d3:40:c2:60
Sep 14 06:22:21  den06-core kernel: %KERN-6-KERN_ARP_ADDR_CHANGE: arp info overwritten for 209.249.232.136 from 6c:8b:d3:40:c2:60 to e4:38:83:84:6a:76
Sep 14 06:22:21  den06-core kernel: %KERN-6-KERN_ARP_ADDR_CHANGE: arp info overwritten for 209.249.232.136 from e4:38:83:84:6a:76 to 6c:8b:d3:40:c2:60
Sep 14 06:34:27  den06-core kernel: %KERN-6-KERN_ARP_ADDR_CHANGE: arp info overwritten for 209.249.232.135 from 6c:8b:d3:40:c2:60 to e4:38:83:84:6a:76
Sep 14 06:34:27  den06-core kernel: %KERN-6-KERN_ARP_ADDR_CHANGE: arp info overwritten for 209.249.232.135 from e4:38:83:84:6a:76 to 6c:8b:d3:40:c2:60

The two mac addresses indicate that a Cisco device and Ubiquiti device are claiming the ip address.  So it appears that the 209.249.232.135 has been configured on two devices or devices behind these devices.  If the device is a router/firewall/switch, the configured device might be a host connected to them.  

You can lookup vendors via mac address here.

https://macaddress.io/mac-address-lookup/aR91pXY3RP

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Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP - Retired)
http://puluka.com/home
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