Virtualization runs many isolated systems on one piece of hardware. It shows up at three levels that the…
By the end of this you’ll know the exact command to confirm a machine’s IP address, subnet mask,…
A Power over Ethernet switch sends both data and electricity down the same cable. That one fact is…
Every cable in a network is one of two things: copper or glass. Copper twisted pair is cheap,…
Three things decide how a Wi-Fi network behaves: the radio band it transmits on, the name it advertises,…
A switch with an empty MAC address table behaves like a hub: the first frame it ever sees…
When a Cisco link misbehaves, the interface counters usually told you why long before anyone noticed the slowdown.…
Before you can design a network, you have to know which shape it should take, and that shape…
Every network you have ever used is built from a small set of device types, and each one…
IPv6 exists because the 32-bit IPv4 address space ran out: roughly 4.3 billion addresses was never going to…
TCP and UDP are the two transport protocols that carry almost all network traffic, and the choice between…
Two models describe how a network moves data: the seven-layer OSI model and the TCP/IP model that the…
