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Renewing Expired Samba DC Certificate

When It's first installed, Samba4 autogenerates self-signed certificate files(ca.pem, cert.pem, and key.pem). These files will be expired 700 days after creation. With the following procedure, the certificate can be renewed. Suppose that the Domain Name is "example.lcl" and the fully qualified DC hostname is "sambadc.example.lcl".  I should also mention that the Linux Distro I'm using is CentOS 8. First, create certificate files using the openssl command; # openssl req -newkey rsa:2048 -keyout EXLCL-Key.pem -nodes -x509 -days 730 -out EXLCL-Cert.pem Generating a RSA private key .........................................+++++ ...........................................+++++ writing new private key to 'EXLCL-Key.pem' ----- You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some bl
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Audit and Send User commands to Syslog in Linux

It is important to monitor every command a system admin or operator executed on the servers. Additionally logging the changes made to systems are required to comply with information security legislation like ISO 27001. In Linux, it can be possible using a simple function. Once you have a remote Rsyslog Server configured, append the following function and trap to /etc/profile file. /etc/profile file is sourced when a shell login occurs. So every time a command is executed, trap named trap_ cmd_to_syslog calls the send_cmd_to_syslog function. ${remote_host} is extracted from the $(who am i)  command. $BASH_COMMAND is the command currently being executed or about to be executed.

How to pass through CSRF protection for Python-Django application using Curl

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Listing Zimbra Accounts with Some Details

Recently I have to export the user list for a particular domain. Luckily Zimbra has Admin GUI with a search feature. When you search accounts, you can download search results as a comma-separated csv file. So I did a search and download the result file, but the result did not have all the columns I need and also there is no option for customizing columns for search results. So I had to write a bash script to get the desired list. Here is the bash script ( It can be customized by adding or removing field names. Run it under zimbra user like ./ <domain_name_here> ):

Creating Multiple VLANs over Bonding Interfaces with Proper Routing on a Centos Linux Host

In this post, I am going to explain configuring multiple VLANs on a bond interface. First and foremost, I would like to describe the environment and give details of the infrastructure. The server has 4 Ethernet links to a layer 3 switch with names: enp3s0f0, enp3s0f1, enp4s0f0, enp4s0f1 There are two bond interfaces both configured as active-backup bond0, bond1 enp4s0f0 and enp4s0f1 interfaces are bonded as bond0. Bond0 is for making ssh connections and management only so corresponding switch ports are not configured in trunk mode. enp3s0f0 and enp3s0f1 interfaces are bonded as bond1. Bond1 is for data and corresponding switch ports are configured in trunk mode. Bond0 is the default gateway for the server and has IP address Bond1 has three subinterfaces with VLAN 4, 36, 41. IP addresses are,, respectively. Proper communication with other servers on the network we should use routing tables. There are three