Question : How does an ISP protect dedicated hosting network

We are looking to set up dedicated and semi-dedicated servers, where clients will have administrative access to servers on our hosting network.

How do we set up a secure hosting environment, so that a compromise of any single machine (intentionally by a client, or being hacked) does not endanger the rest of the network? how do isps do this?

Answer : How does an ISP protect dedicated hosting network

Hi,

"so that a compromise of any single machine (intentionally by a client, or being hacked) does not endanger the rest of the network?"

Well to be honest I was System Administrator of one of America's largest hosting company and this was one of the problems. All DDoS attacks compromised the whole subnet and as a result all servers used to go down. Safety measurements that we used to adopt were that we always had monitors on the System Uptime and load. Whenever there was an attack originated from one server we immediately put that server offline. You need to have such monitoring applications installed in your network. There should be IPS (Hardware-based) installed so that intrusion is not only detected but also prevented. Each server should have BFD (Brute Force Detection)as well as Socket monitors installed.
In short you need to make a fool proof security plan to ensure that your hosting servers are protected which includes very basics like applying patches of applications and services.