Category Archives : Sys admin


ldap on ubuntu

FIRST OF ALL, it would be uber helpful if you first stop the naming service.  Otherwise, it will screw you up and confuse you.  Thus: service nscd stop   /etc/ldap.conf is used for authentication /etc/ldap/ldap.conf is used by other programs to contact the ldap server (pam) To connect to Active directory, you need to map […]


ssh keys don’t work

After copying A’s id_rsa.pub’s content to destination machine B’s .ssh/authorized_keys if it still for some reason prompts you for password when you ssh from A to B, check B’s home directory permissions. It can’t be group writable. Try 744. (755 also works)


ssh tunneling and vnc

vnc is insecure by nature. Thus, use it through ssh tunneling: ssh -L 999:localhost:5900 <—on local host port 999, listen for local connections, and “bind it to remote host’s localhost:5900 (remote host’s localhost = remote host). Now, vnc to localhost port 999. It’ll go through ssh’s port 22.


add people to sudo list

edit /etc/sudoers or whatever softlink it points to. You can do so by: 1. (dangerous way, NOT recommended) chmod the sudoers file. MAKE SURE YOU DO THIS AS ROOT AND NOT SUDO CHMOD, since this will lock you out (sudoers file need to be at 440 permission in order for sudo to work, i.e. once […]