A jump host (also called bastion host) is a specially hardened server that serves as the sole entry point to a secured network zone. Administrators first connect to the jump host and then access target systems from there. This prevents direct access from less trusted networks. In your ISMS, the jump host is a key measure for network segmentation and access control. All sessions through the jump host should be logged to ensure traceability. Keep the jump host minimally configured: only services necessary for access, strict authentication (ideally MFA), and regular hardening reviews.