Linux

Generally speaking, mod_rewrite converts clean and user-friendly URLs to websites. As you can tell by its name, it rewrites the URL. A great way to clear your website’s URLs.

How Apache mod_rewrite Works

When a user enters a URL, the URL is checked against a list of predefined rules. The rules are to search for specific phrases or keywords. If the URL contains the keyword and conforms to the rule, it will be replaced by a predetermined set of URLs.

Nameserver is the name servers that will be used for DNS query of your domain name. Thanks to the nameservers records you will create under Centos web panel when you add a domain to your panel, you can have the added domain redirected to your server. When you redirect the domain name that you added to Centos Web Panel to NS nameservers, that domain will be opened under your server.

Who is using it?

Firewalld is used in the following Linux distributions as the default firewall management tool:

• RHEL 7, CentOS 7
• Fedora 18 and newer
• Available for several other distributions

The most distinctive feature of Firewalld compared to IPTables is that it uses zones. Zone rules apply. Each zone can use different configurations. You can change all the rules that you apply by changing these zones.

Firewall-cmd is the most basic command we will use.

Login to Mysql with an authorized user.

> mysql -u root -p

If more than one database exists, it can be listed with the following command.

> show databeses;

Then the database where the user is located is selected.

> use “database_name”;

The following command also lists the tables in the database.

> show tables;

You can list the fields in the table with the following command.

> describe “tables_name”;

You can use the following command to see all the data in the table.

It should be protected from attacks such as IP Flooding or DDOS, which in fact is the worst of the types of attacks and still has no complete solution to prevent over the world. In this case, servers on the network must hide the outside world. Hiding ICMP packets will be a starting point for this, which should already be hidden for critical servers.

This configuration can be done through firewalls above, but the method we will talk about here is to show that this process can be done in the Linux kernel module, there are many parameters like this in Linux kernel modules and these parameters are examined separately for each process and these parameters are examined individually. It must be configured. The kernel parameter for this change is the module “net.ipv4.icmp_echo_ignore_all. Now we should take a look at how to do these operations, but let’s take a look at what the default parameter of this variable is and see if it is “0”.