CompTIA Exam Prep - ITF+, A+, Network+, Security+, CySA+

Geographic restrictions — also called geofencing , geolocation-based access control , or simply geo-blocking — limit access to systems and data based on where the request appears to originate. They show up on the Security+ exam in two distinct contexts, and conflating them is the common mistake. Geographic restrictions are used both as an access control, deciding who may connect, and as a compliance control, deciding where data may physically live. The Two Uses As an access control. If your organization operates only in North America, there is no legitimate reason for an authentication attempt from another continent. Blocking or challenging those requests removes a large volume of opportunistic attack traffic immediately, and it is one of the cheapest risk reductions available. As a compliance control — data sovereignty. A great many regulations require that certain data stay within a jurisdiction. GDPR constrains transfers of EU personal data outside the EEA. Various nation...

Linux permissions look cryptic until you see the pattern, and then they are genuinely simple. Every file and directory has an owner, a group, and a set of three permissions applied to three categories of user. That is the whole model. Three permissions — read, write, execute — applied to three audiences: the owner, the group, and everyone else. Reading the Output of ls -l A listing line begins with something like -rwxr-xr-- . Ten characters, and each position means something specific. Position 1: the file type. - is a regular file, d a directory, l a symbolic link, c a character device, b a block device. Positions 2–4: the owner's permissions. Positions 5–7: the group's permissions. Positions 8–10: everyone else — "other". So -rwxr-xr-- is a regular file where the owner can read, write and execute; the group can read and execute; and everyone else can only read. The Numeric Shorthand Each permission has a value, and you add them. Permissio...