Restrict Users to Use Old Passwords This is very useful if you want to disallow users to use same old passwords. The old password file is located at /etc/security/opasswd. This can be achieved by using PAM module. [root@localhost ~]# cat /etc/pam.d/system-auth #%PAM-1.0 # This file is auto-generated. # User changes will be destroyed the next … Continue reading RESTRICT USERS TO USE OLD PASSWORDS
Month: April 2016
domain mapping
How To Map DOMAIN & IP on cloud set-up Purchase a server from any cloud server selling vendor EX:I have purchased a one virtual machine from godaddy and  static-IP address assigneed to it is "192.169.170.133" try ping ans ssh to server mohammedrafi@NOC-RAFI:~$ ping 192.169.170.133 PING 192.169.170.133 (192.169.170.133) 56(84) bytes of data. 64 bytes from 192.169.170.133: … Continue reading domain mapping
vmstat,iostat,mpstat
vmstat,iostat,mpstat commands for (Performance Observation) vmstat – Summary information of Memory, Processes, Paging etc. vmstat reports virtual memory statistics. [root@li1250-113 ~]# yum provides */bin/vmstat And install the package which is not there [root@li1250-113 ~]# vmstat procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r  b  swpd  free     buff  cache   … Continue reading vmstat,iostat,mpstat
patching
Patching Work [root@PEARLSCRIPT ~]# rpm -qa glibc glibc-2.12-1.166.el6_7.3.x86_64 [root@PEARLSCRIPT ~]# yum update glibc Loaded plugins: product-id, refresh-packagekit, security, subscription-manager Setting up Update Process Resolving Dependencies --> Running transaction check ---> Package glibc.x86_64 0:2.12-1.166.el6_7.3 will be updated --> Processing Dependency: glibc = 2.12-1.166.el6_7.3 for package: glibc-headers-2.12-1.166.el6_7.3.x86_64 --> Processing Dependency: glibc = 2.12-1.166.el6_7.3 for package: glibc-devel-2.12-1.166.el6_7.3.x86_64 --> … Continue reading patching
banner
How To Set Up BANNER       IF U WANT TO SEE THE BANNER BEFORE LOGIN THIS IS PROCEDURE [root@ORACLE ~]# cat /etc/issue.net Red Hat Enterprise Linux Server release 6.7 (Santiago) Kernel \r on an \m [root@ORACLE ~]# cat >> /etc/issue.net #################################### #########WRITE WHAT EVER U WANT TO RIGHT######### ######################################################## [root@ORACLE ~]# … Continue reading banner
Monitor User Activities
psacct or acct both are similar packages and there is not much difference between them, but the psacct package only available for rpm based distributions such as RHEL, CentOS and Fedora, whereas acct package available for distributions like Ubuntu, Debian and Linux Mint. [root@localhost ~]# yum provides psacct Loaded plugins: fastestmirror, refresh-packagekit, security Loading mirror … Continue reading Monitor User Activities
logs
Review Logs Regularly Move logs in dedicated log server, this may prevents intruders to easily modify local logs. Below are the Common Linux default log files name and their usage: /var/log/message – Where whole system logs or current activity logs are available. /var/log/auth.log – Authentication logs. /var/log/kern.log – Kernel logs. /var/log/cron.log – Crond logs (cron … Continue reading logs
RED HAT ENTERPRISE LINUX HARDENING CHECKLIST
Red Hat Enterprise Linux Hardening Checklist Preparation and Physical Security If machine is a new install, protect it from hostile network traffic until the operating system is installed and hardened. Set a BIOS/firmware password. Configure the device boot order to prevent unauthorized booting from alternate media. Use the latest version of RHEL possible. Filesystem Configuration … Continue reading RED HAT ENTERPRISE LINUX HARDENING CHECKLIST
simple commands
Introduction to LINUX (Basic Commands) [root@localhost ~]# hostname localhost.localdomain [root@localhost ~]# ifconfig eth0    Link encap:Ethernet  HWaddr 00:0C:29:63:46:BD inet addr:172.16.28.145  Bcast:172.16.28.255  Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe63:46bd/64 Scope:Link UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1 RX packets:2332 errors:0 dropped:0 overruns:0 frame:0 TX packets:1455 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:257468 (251.4 KiB)  TX bytes:192203 (187.6 KiB) … Continue reading simple commands
rhel-7 or centos-7
Make Rhel-7 & in Graphical mode                  How To make rhel-7 as graphical desktop yum grouplist yum groups install "GNOME Desktop" or yum groupinstall "GNOME Desktop" yum groups install "Server with GUI" or yum groupinstall "Server with GUI" systemctl … Continue reading rhel-7 or centos-7
