📄️ TCP/IP Stack
The TCP/IP stack defines layered packet processing from link to application. The kernel handles encapsulation, routing, and connection state.
📄️ Subnetting
Subnetting divides IP networks using netmasks to control address ranges and broadcast domains.
📄️ Ethernet, ARP, and RARP
Ethernet operates at Layer 2 carrying frames. ARP resolves IPv4 addresses to MAC addresses. RARP is obsolete.
📄️ DNS
DNS maps hostnames to IP addresses via recursive or iterative queries.
📄️ IP Routing
Routing determines next hop based on kernel routing tables.
📄️ DNS Resolution (glibc resolver)
DNS resolution in Linux uses /etc/resolv.conf, NSS modules, and caching resolvers.
📄️ Netfilter
Netfilter handles packet filtering, NAT, and connection tracking via kernel hooks.
📄️ SSH
SSH provides secure remote shell access using encrypted TCP connections.
📄️ File Transfer
Linux uses scp, sftp, rsync, and other tools for transferring files over the network.