Network Adapter Configuration
Access network settings: Control Panel → Network and Sharing Center → Change adapter settings, or right-click the network icon in the taskbar. Per-adapter settings: right-click adapter → Properties → Internet Protocol Version 4 (TCP/IPv4) → Properties. Obtain IP automatically (DHCP): default for most clients. Use the following IP address: manually enter IP address, subnet mask, default gateway. Preferred DNS server, Alternate DNS server. Advanced settings: multiple IP addresses, DNS suffix, WINS. Obtain DNS server address automatically: uses DHCP-provided DNS. Adapter properties also accessible via Device Manager. Disable/enable adapter: right-click → Disable / Enable. Diagnose: right-click → Diagnose (runs Windows Network Diagnostics). Status: right-click → Status → Details (shows IP, MAC, DHCP lease info, DNS server, gateway).
Workgroup vs Domain
Workgroup: peer-to-peer network model. Each computer manages its own user accounts and security. No central authentication. User accounts must be created on each computer independently. Maximum practical size: 10-20 computers. Setup: System Properties → Computer Name → Change → Workgroup. Default workgroup name: WORKGROUP. Domain: client-server model using Active Directory (AD). Centralized user accounts, group policies, and authentication via domain controllers (DCs). Single sign-on: one set of credentials grants access to all authorized resources. Computer must be joined to the domain: System Properties → Computer Name → Change → Domain → enter domain name (requires Domain Admin credentials). DNS must point to the domain controller. Domain controller (DC): Windows Server running Active Directory Domain Services (AD DS). Organizational Units (OUs): containers within AD for organizing users, computers, and groups.
Network Discovery and File Sharing
Network Discovery: allows a computer to see other computers and devices on the network. Control Panel → Network and Sharing Center → Change advanced sharing settings. Network profiles: Private (home/work) — network discovery and file sharing on by default. Public — both off by default (more restrictive). Domain — controlled by group policy. File and Printer Sharing: must be enabled to share resources. HomeGroup (removed in Windows 10 1803): was a simplified home sharing feature. Replaced by standard workgroup sharing. SMB (Server Message Block): protocol used for Windows file sharing. `\servernamesharename` — UNC (Universal Naming Convention) path format. Map network drive: File Explorer → This PC → Map network drive (assigns a drive letter). `net use Z: \servershare` from command line.
Windows Firewall
Windows Defender Firewall: built-in stateful firewall. Filters inbound and outbound traffic by application, port, or IP address. Access: Control Panel → Windows Defender Firewall, or Windows Security → Firewall & network protection. Profiles: Domain (active when on a domain network), Private, Public. Allow an app through firewall: Windows Defender Firewall → Allow an app or feature through Windows Defender Firewall. Advanced settings: Windows Defender Firewall with Advanced Security (wf.msc) — create granular inbound/outbound rules by port, protocol, program, scope. Blocking ports: create inbound/outbound rules to block specific ports. Turn off firewall: not recommended; should only be done for specific troubleshooting. `netsh advfirewall` command-line management. netsh winsock reset: resets Windows Sockets (fixes network stack corruption).
Proxy Settings
A proxy server acts as an intermediary between client and internet. Uses: content filtering, anonymization, caching, bandwidth control. Windows proxy settings: Settings → Network & Internet → Proxy. Options: Automatic proxy detection (WPAD protocol), Use setup script (PAC file URL), Manual proxy (IP:port). Proxy settings also configurable in Internet Options (iexplore) → Connections → LAN settings. Some applications have separate proxy settings (Firefox, Java). System proxy vs browser proxy: system proxy applies to WinInet-based applications (IE, Edge, Windows Update). Other applications may bypass system proxy. WPAD (Web Proxy Auto-Discovery): uses DNS or DHCP to automatically provide proxy configuration. PAC (Proxy Auto-Configuration) file: JavaScript script that determines whether to use a proxy for a given URL.
VPN Configuration
VPN (Virtual Private Network): creates an encrypted tunnel over the internet to a private network. Use cases: remote workers accessing corporate resources, secure use of public Wi-Fi. Windows built-in VPN client: Settings → Network & Internet → VPN → Add a VPN connection. Requires: VPN provider (Windows built-in), Connection name, Server name or address, VPN type (PPTP, L2TP/IPSec, SSTP, IKEv2). Common VPN protocols: PPTP: older, faster, weaker security (avoid). L2TP/IPSec: widely supported, good security (uses pre-shared key or certificates). SSTP: SSL-based, works over port 443 (penetrates most firewalls). IKEv2: fast reconnection (mobile devices), strong security. Split tunneling: only corporate traffic goes through VPN; internet traffic uses local connection directly. Always-on VPN: enforced by MDM policies for corporate devices.