The Dynamic Host Configuration Protocol (DHCP) automatically configures network settings for a host so that these settings do not need to be configured on the host statically. Given the rapid and programmatic provisioning of resources within a cloud environment, this capability is crucial to cloud operations. Both DNS and its security-integrity extension DNSSEC provide name resolution to IP addresses, but neither is used for the configuration of network settings on a host. DCOM refers to the Distributed Component Object Model, which was developed by Microsoft as a means to request services across a network, and is not used for network configurations at all.

All the others might be included in data labels, but we don't usually include data value, since it is prone to change frequently, and because it might not be information we want to disclose to anyone who does not have need to know.

Explanation
Virtual private networks (VPNs) are used to provide administrative personnel with secure communication channels through security systems and into trust zones. They allow staff who perform system administration tasks to have access to ports and systems that are not allowed from the public Internet. IPSec is an encryption protocol for point-to-point communications at the network level, and may be used within a trust zone but not to give access into a trust zone. TLS enables encryption of communications between systems and services and would likely be used to secure the VPN communications, but it does not represent the overall concept being asked for in the question. SSH allows for secure shell access to systems, but not for general access into trust zones.