Question : Some machines can ping the server, others cannot

I have some users who can ping the machinename and the IP. I have other users who cannot ping the machinename or IP.

I have tried ipconfig /flushdns and then ipconfig /registerdns on the machines that cannot see it. No change. They can still not ping the IP.

Any ideas?

This is on a domain, with multiple DC's and multiple DNS servers for failover. I checked all the servers and everything looks fine. All the other servers people can ping by host and IP. Just this one is giving me issues.

Answer : Some machines can ping the server, others cannot

If they can't ping by IP address then you have a network problem. I would start testing to make sure that your network is working properly maybe switching ports checking VLAN setup, replacing the nic, and etc.