You can use split DNS to namespace internal services in such a way that attackers from the public internet can’t easily use names of internal services to attack them from outside. Some client operating systems such as FreeBSD do not have native split DNS configuration support, so you will need to have a backup DNS server that does that split DNS querying for you. This setup is fraught with opportunities for error and is typically very easy to mess up, which can have unexpected effects across your network. This is typically configured by using the native DNS configuration interface for every client operating system you use. This also helps prevent DNS cache poisoning attacks that could let an attacker access cookies or other secrets for internal services. This has been used to provide security through obscurity because it allows you to hide the names of internal network resources from external clients. to an internal DNS server so that you can privately expose services without the DNS names being visible to the public internet. This allows you to send queries for every domain ending in. Then you need to configure your computer to “split up” its queries between different servers. When you set up a split DNS (also known as “split horizon”) configuration, you create a DNS server that answers with a set of records that aren’t used on the public internet. Without this critical invention, the modern internet would not be possible. DNS was designed to have the same questions result in the same answers everywhere in the world, which allows users to never have to think about IP addresses. Over time, this has become one of the most important protocols of the internet, but most people outside the networking world have little or no understanding of it. DNS receives questions like “What is the IPv4 address of ?” and responds with answers like 37.16.9.210. In most networks, this translation is done with a protocol called Domain Name System (DNS). But computers want to be able to connect to IP addresses, so there needs to be some kind of translation step. Some people are able to remember these easily, but most people find it easier to remember names like instead of IP addresses like 37.16.9.210. IP addresses are either assigned to every network interface (such as the ethernet or Wi-Fi card used to connect to that network) by the router, or they are randomly assigned by convention, depending on which version of IP is being used. In most cases, each device on a network will have its own IP address. Each one also needs to be able to identify every other device on that network uniquely. When you connect devices together in the same network, each device needs to be able to communicate with every other device.

Pam splitt