Change MySQL user's password in bulk Sometimes we need to change the password of mysql users at bulk. Lets say your company has fired a group of peoples or dissolved a project. This requirement can be supplied as : We can achieve the same by changing the password field in mysql.user table. Password() is a predifined method in mysql which generates encrypted value of a certain string. host update mysql.user set password = PASSWORD("passwd") where host IN (<Comma separated list of HostName/IP>); user update mysql.user set password = PASSWORD("passwd") where user IN (<Comma separated list of ‘user’@’host’>);
Allowing users to have ssh access Hi Readers, It is one of the tasks we need to complete in order to allow users to log-in into your server without compromising your security. We are going to accomplish the following tasks, 1.) Allow the users for given domain only 2.) Must allow access to a given domain 3.) Block access for a specific domain. These questions are asked in RedHat certification examination RHCE6 We are going to complete the above mention task using iptables To give proper example we are taking 192.168.20.0/255.255.255.0 as our domain and 192.168.21.0/255.255.255.0 as other domain. Assuming that your system is a fresh installation we can remove all rules previously applied. # iptables -F The above mention command will flush all the previously applied rules. Insert a rule in your input chain by below mention command, # iptables -I INPUT -s <ip of your domain>/<subnet mask> -p <protocal tcp/udp> --dport <port> -...