Posts Tagged ‘administration’
Changing the port number of SSH daemon is a quick way of reducing the number of SSH brute force attacks your server might face (check the file /var/log/auth.log to see if there are many failed SSH login attempts). Just to be on the safe side, create a backup copy of the SSH daemon config file. [...]
Here are a few things you can try if you get the BADSIG error in Update Manager: Run the following commands from terminal shell: sudo apt-get clean sudo apt-get update -o Acquire::http::No-Cache=True Change the Ubuntu server from which updates are downloaded: System > Software Sources > Ubuntu Software tab > change the selected server in [...]
Sometimes you may want to log in with a different user account in Terminal without logging out from your X session or switching to an unused virtual console. There are two different approaches to do this in Ubuntu: interestingly, it is possible without even knowing the other user’s password. Approach 1: if you know the [...]
Oracle Database XE (Express Edition, sometimes also referred to as Apex) comes with an embedded web interface for administration. By default the HTTP port of this web interface is 8080. This can be checked by running the query below when logged in as system: SQL> select dbms_xdb.gethttpport from dual; In order to change the port [...]
My recent misadventures with adding a group membership for my user and in the process managing to remove all other groups (including admin) got me thinking about the message “… is not in the sudoers file. This incident will be reported.” Exactly where and how and to whom is this reported? Well, according to clever [...]
This article on The Register has a link to a very good page on CentOS website with tips on securing OpenSSH. The tips are applicable for all distros, not just CentOS, and are definitely worth going through and implementing if you have SSH enabled on your server. Good luck and stay secure.
Here is a very simple one which caught me out: you want to add your user to a group through command line. The command is very straightforward: sudo usermod -aG tools hammer This adds the user “hammer” to the group “tools”. Notice the -a switch (for add). This means “hammer” will become member of “tools” [...]