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Ruankao Network Planning Designer (Senior) study materials
Ruankao Network Planning Designer (Senior) study resources

Ruankao Network Planning Designer (Senior): Network Operating Systems, Servers and Application Services

Ruankao Network Planning Designer (Senior) · Work through your exam, one topic at a time.

All guide sections

Network Operating Systems, Servers and Application Services

Server-side knowledge is tested through role configuration, permissions arithmetic and storage/availability design. Expect a permission-intersection question and a RAID capacity question.

Windows Server roles

  • AD DS provides centralised authentication via domains, OUs and Group Policy; DNS is usually integrated with AD.
  • Standard roles: DNS, DHCP, IIS (web), file and print, Hyper-V, Remote Access/VPN, Windows Deployment Services.
  • File sharing combines share permissions with NTFS permissions; the effective access is the most restrictive of the two. NTFS permissions are cumulative across groups, and permission evaluation follows explicit/inherited entries and the actual access-check rules; a simple deny slogan can hide important inheritance details. Moving a file within the same volume keeps permissions; copying inherits from the destination.

Linux servers

  • Filesystem hierarchy: /etc configuration, /var variable data including logs, /home users, /usr programs, /tmp temporary.
  • Permissions rwx map to 4/2/1; chmod 755 file gives owner rwx, group and others r-x. Ownership changes with chown user:group.
  • Key configuration files: /etc/httpd/conf/httpd.conf (or /etc/nginx/nginx.conf), /etc/named.conf with zone files, /etc/vsftpd/vsftpd.conf, /etc/ssh/sshd_config, and network settings under /etc/sysconfig/network-scripts or /etc/netplan. Services are managed by systemctl.
  • Remote administration over SSH (22); verify listening sockets with ss -lntp.

Storage and virtualisation

  • RAID 0 stripes with no redundancy; RAID 1 mirrors; RAID 5 stripes with parity (tolerates one failure, usable capacity (n−1)×disk); RAID 6 tolerates two; RAID 10 mirrors then stripes.
  • Type 1 hypervisors run on bare metal (ESXi, Hyper-V, KVM); type 2 run on a host OS (VirtualBox, VMware Workstation). Snapshots preserve a point-in-time state; independent retained copies can contribute to backup, while a same-store snapshot alone does not protect against loss of that store. Live migration can use different storage arrangements depending on the platform.

Worked example

A server has four 2 TB disks in RAID 5. Usable capacity is (4−1) × 2 TB = 6 TB, and it survives one disk failure. The same four disks in RAID 10 give 4 TB usable and tolerate one failure per mirrored pair. A share permission of Read combined with NTFS Modify for a user yields Read - the stricter wins.

Traps that cost marks

  • Adding share and NTFS permissions instead of taking the most restrictive.
  • Assuming RAID 5 survives two simultaneous failures.
  • Confusing snapshot with backup, or forgetting that snapshots consume storage.
  • Editing configuration but not restarting or reloading the service.