hi all, this document deals with the explanation of bind address-security.
You might have heard about bind-address when configuring certain applications such as Redis, MongoDB, elasticsearch, etc wherein the configuration to choose or configure bind address.
Initially, during my starting of my career, I was not knowing what is the use of configuring bind addresses during I do some of the installations. Later going to through hardening servers came to know how important is configuring bind addresses it is.
Bind address as the name indicates to which address the service needs to be bound. Usually, I was giving 0.0.0.0 because that made my installation easy and smoother.
I will explain what is the problem by configuring the bind-address as 0.0.0.0
Let’s assume the server where you are configuring MariaDB has 3 network interfaces. All four NICs of the same server might be using for 3 different functions. May all 3 Nics can be from different LAN segments. When you configure bind address as 0.0.0.0 for MySQL service. The Mysql service can be access from any of these NICs if the firewall connection is allowed on the server.
Once you configure the listening address of the MySQL service becomes like this 0.0.0.0:3306, This you can verify when you do the netstat -tulnp command.
Now let’s assume in this case, now you reconfigured the bind-address 172.30.1.12. After the restart, the service of MySQL executes the netstat -tulnp command. Now you can see the listening address changed from 0.0.0.0:3306 to 172.30.1.12:3306 . If you try to access from any other subnet server which is other than 172.30.1.0 series the connection get rejected even though the firewall access is enabled. This because of the service bound use above address. Another subnet can access until there is routing made between all the subnets.
There are certain services that allow multiple bind addresses.
© 2020, Techrunnr. All rights reserved.