Sys Admin

How to installing Postfix and Dovecot on Linux CentOS yum install postfix dovecot chkconfig postfix on chkconfig dovecot on  Configure main.cf : vi /etc/postfix/main.cf # change or add on these line: myhostname = mail.fileregion.com mydomain = fileregion.com myorigin = $mydomain inet_interfaces = all mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain mynetworks = 127.0.0.0/8 home_mailbox = Maildir/ smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth smtpd_sasl_auth_enable = yes smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, permit broken_sasl_auth_clients = yes Restarting postfix: /etc/init.d/postfix restart Configure Dovecot on Linux CentOS 6 Configure dovecot.conf: vi /etc/dovecot/dovecot.conf # uncomment on this line: protocols = imap pop3 listen = * Config mail auth mehanism: vi /etc/dovecot/conf.d/10-auth.conf # change on these line: disable_plaintext_a

1. Install Tigervnc Server view plain copy to clipboard print ? [root@demo ~]# yum -y install tigervnc-server   2. Install X Windows and GNOME. This used to be yum groupinstall "X Window System" "GNOME Desktop Environment", but is now simply: view plain copy to clipboard print ? yum groupinstall  "X Window System"   "Desktop"    3. Create a user (or use and existing user) and create VNC login. view plain copy to clipboard print ? [root@demo ~]# useradd david   [root@demo ~]# passwd david   Changing password  for  user david.   New password:   Retype  new  password:   passwd: all authentication tokens updated successfully.   [root@demo ~]# su - david   4. Switch to the user (su - user) and issue 'vncpasswd' to set the VNC password view plain copy to clipboard print ? [david@demo ~]$ vncpasswd   Password:   Verify:   [david@demo ~]$   5. Start VNC using 'vncserver :1'

Setting up a Linux for dhcp can be done by editing file using a text editor such as vi: # vi /etc/sysconfig/network-scripts/ifcfg-eth0 Following is sample static configuration: DEVICE=eth0 BOOTPROTO=static HWADDR=00:19:D1:2A:BA:A8 IPADDR=10.10.10.10 NETMASK=255.255.255.0 ONBOOT=yes Replace static configuration with DHCP: DEVICE=eth0 BOOTPROTO=dhcp HWADDR=00:19:D1:2A:BA:A8 ONBOOT=yes Save and close the file. Just restart network service:

Here we will see a technique  how to spoof MAC address in Linux . MAC address spoofing is changing the Media Access Control (MAC) address of the network interface card (NIC). First of all let me tell you that the MAC address or the Hardware address is inbuilt and is actually burnt into your NIC interface card at the time of manufacturing. It is unique worldwide and cannot be changed permanently by the use of any kind of software. That being said, however we can change it temporarily to suit our needs. The method described here can be used in RHEL, CentOS and Ubuntu as well. MAC address is 48 bits hexadecimal address. Before directly changing the address you need to find out the current MAC address of your network card by using the command # ifconfig | grep HWADDR It will give you output as eth0 Link encap:Ethernet HWaddr 00:21:5A:9B:00:F0 The MAC address in this case is 00:21:5A:9B:00:F0 How to spoof / change MAC address in Linux To change it use the ifconfig com

Some useful windows 8 keyboard shortcuts: Shortcut Description  +  D Show Desktop  +  C Open Charms Menu  +  F Charms Menu – Search  +  H Charms Menu – Share  +  K Charms Menu – Devices  +  I Charms Menu – Settings  +  Q Search For Installed Apps  +  W Search Settings  +  Tab Cycle through open Modern UI Apps  +  Shift  +  Tab Cycle through open Modern UI Apps in reverse order  +  . Snaps app to the right (split screen multitasking)  +  Shift  +  . Snaps app to the left (split screen multitasking)  +  , Temporarily view desktop Alt  +  F4 Quit Modern UI Apps  +  E Launch Windows Explorer Window  +  L Lock PC and go to lock screen  +  T Cycle through icons on taskbar (press  Enter  to launch app)  +  X Show Advanced Windows Settings Menu  +  E Launch Windows Explorer Window  +  Page Down Moves Start screen and apps to secondary monitor on the right  +  M Minimize all Windows  +  Shift  +  M Restore all minimized Windows  +  R Open Run dialog box  +  Up Arr