Interfaces, addresses and subnets

Articles

• Network diagnostics — A ladder of connectivity checks — from the gateway to DNS and the destination port.
• ping — check whether packets reach a host — The ping command sends ICMP echo requests to a host and prints replies, latency and loss — the first network check.
• ip — addresses, interfaces and routes — Manage interfaces, addresses and routes (iproute2) — the replacement for ifconfig/route.
• The veth pair and network namespaces — A veth pair is two virtual interfaces joined like a cable; it connects network namespaces inside one machine.