Arduino with SNMP

Hi, i'm doying a project that I can monitor the temperature of datacenter using arduino + ethernet shield + lm 35 using SNMP protocol.

When I add a private IP on my arduino, I can collect the SNMP, but if I add a public IP, I can't. I've tryed a professional temp monitor with the same IP, and works. I haven't firewall , so the firewall isn't the problem. The Agentuino library has a firewall or ACL control or something like this?

When I add a private IP on my arduino, I can collect the SNMP, but if I add a public IP, I can't.

That's most probably not an Arduino problem but a routing problem in your network. I doubt that you can use private and public IPs in the same network segment in your datacenter (at least I hope so).