Networking on Vinh Phamhttps://vinhdata.com/tags/networking/Recent content in Networking on Vinh PhamHugo -- gohugo.ioenVinh PhamTue, 13 Oct 2026 10:08:00 +0700Securing the path: keys, certificates, TLS, IPsec and firewallshttps://vinhdata.com/writing/2026/networking-foundations-8-securing-the-path/Tue, 13 Oct 2026 10:08:00 +0700https://vinhdata.com/writing/2026/networking-foundations-8-securing-the-path/Every router on the path can read, change or replay a packet. TLS seals one connection after a certificate proves the server’s name, IPsec seals everything between two networks, and a firewall decides who may start a connection. Part 8.One link at a time: frames, ARP, switches and the data centerhttps://vinhdata.com/writing/2026/networking-foundations-6-the-link-and-the-data-center/Tue, 13 Oct 2026 10:06:00 +0700https://vinhdata.com/writing/2026/networking-foundations-6-the-link-and-the-data-center/IP picks the next router; the link carries the packet there in a frame addressed to a MAC. ARP finds that address, a switch learns where it lives, and a data center connects many equal paths. Part 6.Routes between networks: BGP, route selection and ICMPhttps://vinhdata.com/writing/2026/networking-foundations-5-routes-between-networks/Tue, 13 Oct 2026 10:05:00 +0700https://vinhdata.com/writing/2026/networking-foundations-5-routes-between-networks/Nobody types the route from one network to another. Routers announce prefixes with the path they took, pick by policy before path length, and use ICMP to say what went wrong. Part 5.Addresses, routes and NAT: what a router does to a packethttps://vinhdata.com/writing/2026/networking-foundations-4-addresses-routes-and-nat/Tue, 13 Oct 2026 10:04:00 +0700https://vinhdata.com/writing/2026/networking-foundations-4-addresses-routes-and-nat/A router reads one address, takes the longest matching row of its table, lowers the TTL and sends the packet on. Subnets, DHCP and NAT decide which addresses it carries. Part 4.TCP, the connection: handshake, numbers, losses and windowshttps://vinhdata.com/writing/2026/networking-foundations-3-tcp-the-connection/Tue, 13 Oct 2026 10:03:00 +0700https://vinhdata.com/writing/2026/networking-foundations-3-tcp-the-connection/TCP numbers every byte and resends what is not acknowledged, so a network that loses packets still carries one ordered stream. How fast that stream runs over a long path is at most the smaller of two windows divided by the round-trip time. Part 3.Names, ports and requests: DNS and HTTP before the first bytehttps://vinhdata.com/writing/2026/networking-foundations-2-names-ports-and-requests/Tue, 13 Oct 2026 10:02:00 +0700https://vinhdata.com/writing/2026/networking-foundations-2-names-ports-and-requests/Before an API call returns its first byte, a resolver turns the name into an address, a socket opens on a port, and HTTP sends a request. Every new connection costs round trips that a kept connection and a cache save. Part 2.Where slow comes from: four delays, the queue and the narrowest linkhttps://vinhdata.com/writing/2026/networking-foundations-1-where-slow-comes-from/Tue, 13 Oct 2026 10:01:00 +0700https://vinhdata.com/writing/2026/networking-foundations-1-where-slow-comes-from/Every hop charges four delays, and distance sets a floor that no faster link lowers. A queue grows sharply near full load, a copy runs at its narrowest link, and a traceroute shows which of these you pay. Part 1.