Category Archives: CentOS
Change host name of Puppet client
Here are the steps i use to change the host name of a puppet client: On the client side stop Puppet, remove old certificates and change host name: Change the host name in /etc/sysconfig/network and /etc/hosts, then reboot the client. Remove the old certificate on the server: If you’re using Foreman, change the host name there too. Finally, initialize a … Continue reading
Plesk (11) – Redirect Webmail to HTTPS
By default the webmail interfaces of Plesk is running unsecured on port 80. That’s bad, really bad (Shame on you Parallels!). There are some guides out there to fix that, but they are all wrong in my eyes. Some are made for old releases, others are changing stuff in files which are overwritten on update or regeneration of config files. But … Continue reading
Limit/prevent SSH brute force attempts
If you (have to) run a public available SSH server, you may have noticed already that there are a lot of brute force attacks trying to guess a user and password (have a look into /var/log/secure ). If you did it the correct way, you only allow public keys to authenticate of course. But maybe you can’t, because the client … Continue reading
Slow DNS lookup on CentOS 6 machines
Slow DNS lookups can have many reasons. Mostly they are easy to fix because it simply is a wrong IP address of the DNS f.ex. But today i had a harder one, but was easy to fix if you know how… Looking up an address with dig works all the time, but when puppet gets its plugins or other files … Continue reading