A bastion host is a 6.3.5 network device that is exposed to attacks and has been hardened against them through tight security measures.
The term that describes a 6.3.5 network device that is exposed to attacks and has been hardened against those attacks is Bastion Host. A bastion host is a highly secured device located on a network perimeter that acts as a dedicated gateway between an internal network and external network, protecting the internal network from unauthorized access. It is specifically designed to withstand attacks and is configured with tight security measures such as strict access control and intrusion detection systems.