First of all, you should know that creating a password-less account is a very bad idea. You should be knowing what you are doing before doing so. However this may be of use in certain scenarios like doing SSH or Telnet to a virtual machines created using Virtualization software like VMWare, KVM, Microsoft Virtual PC etc. In such scenarios you should have a dedicated network adapter for each virtual machine that is accessible to the host machine only. Of course any such management service like SSH, Telnet or FTP should be running only on the adapter accessible to Host system only. Configuring services to listen on specific adapters is out of the scope here.

You must be logged in as “root” user to do this. Okay. Now you know what you are doing.

To create a password-less account in Linux, First you can create the account as usual. In this example, I am trying to create a new user account “mark“.

[root@techpulp ~]# adduser mark

Now set blank password for user “mark”.

[root@techpulp ~]# passwd -d mark

This allows user “mark” to login without a password.