An introduction to DNS zone files. Still in progress, will be: An intermediate-level article on DNS  for experienced UNIX systems administrators.

DNS Administration

A document on how more than one VLAN can be accessed from a single network interface. Includes information on the Cisco and Linux configurations.

Multiple VLANs

Networking is defined by the OSI and TCP/IP models. Here is a comparison of the two with further explanations of the OSI model . and the TCP/IP model. (The TCP/IP model is easier).

The OSI and TCP/IP models

How TCP's ​ three-way handshaking   works

Info on the TCP protocol

Modern Networking
Linux ​ policy routing , SDN (Software-Defined Networking),  NFV (Network Function Virtualization)

Current topics in networking

Port Test
How To Use Python To Test If A TCP Port Can Be Reached 

A Python Script

More documentation being added every week.

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