For some reason, my windows server wouldn’t talk to one of my network devices. It would talk to all the others, but not this one. I tried changing the ip address of the device, and even swapped it out for a similar device of a different model and manufacturer. Still no dice. When I looked closer, I saw that the ip address of the device wasn’t in the arp table on the windows server, so I tried to manually add it.
arp -s IP.Address Mac.Address
Error message, you don’t have sufficient privileges.
Ok, so let’s try this in CMD as Administrator
Error message, permission denied.
A quick google search, and I found that I need to use netsh instead.
netsh interface ip add neighbors "Network card name here" "Gateway.IP.goes.here" "MAC-address-of-gateway-with-dash-here"
bam! Ping and network connectivity fixed. The WHY of this happening is still a mystery however.
I did eventually figure it out. I’d hooked up a bunch of network cameras to my network, and they all had the same address. Multiple simultaneous conflict addresses in the mac table seems to have freaked out my switch. I rebooted the switch, and things seemed to resolve.