Additionally, administrators are better able to control access to resources on the network based on IP address when a deterministic IP addressing scheme is used. This can be especially important for hosts that provide resources to the internal network as well as to the external network. Web servers or e-commerce servers play such a role. If the addresses for these resources are not planned and documented, the security and accessibility of the devices are not easily controlled. If a server has a random address assigned, blocking access to this address is difficult and clients may not be able to locate this resource.