.::: Different Output OID ifDescr & ifAlias :::.

1. Different ifDescr, ifName & ifAlias
ifDescr OBJECT-TYPE
    SYNTAX      DisplayString (SIZE (0..255))
    MAX-ACCESS  read-only
    STATUS      current
    DESCRIPTION
            "A textual string containing information about the
            interface.  This string should include the name of the
            manufacturer, the product name and the version of the
            interface hardware/software."
    ::= { ifEntry 2 }

.::: Sample output snmpwalk OID on MIB IF-MIB :::.

1. Definition IF-MIB
The MIB module to describe generic objects for network interface sub-layers. This MIB is an updated version of MIB-II's ifTable, and incorporates the extensions defined in RFC 1229.

2. OID on IF-MIB include calculate
ifTable
1.3.6.1.2.1.2                            interfaces                                           NODE
1.3.6.1.2.1.2.1                          ifNumber                                             LEAF  Integer32
1.3.6.1.2.1.2.2                          ifTable                                              NODE
1.3.6.1.2.1.2.2.1                        ifEntry                                              NODE
1.3.6.1.2.1.2.2.1.1                      ifIndex                                              LEAF  InterfaceIndex
1.3.6.1.2.1.2.2.1.2                      ifDescr                                              LEAF  DisplayString
1.3.6.1.2.1.2.2.1.3                      ifType                                               LEAF  IANAifType
1.3.6.1.2.1.2.2.1.4                      ifMtu                                                LEAF  Integer32
1.3.6.1.2.1.2.2.1.5                      ifSpeed                                              LEAF  Gauge32

.::: How To Export Display on Linux/Unix Platform (Installer User Interface Mode Not Supported):::.

1. example running java on linux using CLI
[root@TeguhLab /]# su oracle
bash-4.1$ cd /
bash-4.1$ ./teguh.bin
Preparing to install...
Extracting the JRE from the installer archive...
Unpacking the JRE...
Extracting the installation resources from the installer archive...
Configuring the installer for this system's environment...

Launching installer...

Graphical installers are not supported by the VM. The console mode will be used instead...

Preparing CONSOLE Mode Installation...

.::: How to display login banner before & After login(Prelogin, Postlogin) On Unix/Linux :::.

Pre login banner is use for sending a warning message before authentication may be relevant for getting legal protection or just give out information to users. The contents of the specified file are sent to the remote user before authentication is allowed. This option is only available for protocol version 2. By default, no banner is displayed (if you are using latest version of Linux/UNIX then you do not have to worry about version issue)

A. Display SSH Warning Message to Users Before Login

1) By default sshd server turns off this feature.

.::: Enable Crontab on Linux/Unix Platform :::.

Crontab  is  the program used to install, remove or list the tables used to drive the cron(8) daemon.  Each user can have their own crontab, and though these are files in /var/spool/ , they are not intended to be edited directly. For SELinux in mls mode can be even more crontabs - for  each  range.  For  more  see selinux(8).

The  cron jobs could be allow or disallow for different users. For classical crontab there exists cron.allow and cron.deny files.  If cron.allow file exists, then you must be listed therein in order to be allowed to use this command.  If the cron.allow file does not exist but the cron.deny file  does  exist,  then you must not be listed in the cron.deny file in order to use this command.  If neither of these files exists, only the super user will be allowed to use this command.  The second option is using PAM authentication, where you set up users, which could  or  couldn’t  use  crontab  and  also  system  cron  jobs  from /etc/cron.d/.

::: How to Upgrade RHEL/Redhat Enterprise Linux 7 Using Repolocal, ISO & Online :::.

1. capture release version before upgrade
[root@teguhlab yum.repos.d]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.2 (Maipo)
[root@teguhlab yum.repos.d]#

2. Mounting Image Rhel 7.3/Latest Using ISO File or DVD Room/Repolocal
detail on http://teguhth.blogspot.co.id/2017/07/how-settting-install-package-os-redhat.html

3. Clean all
# yum clean all
# subscription-manager clean
All local data removed

.::: How Settting & Install Package OS Redhat Enterprise Linux(Rhel) 7 Using Repolocal, ISO File & rpm file :::.

A. Using Repolocal(DVD)
1. Make sure DVD mounting
[root@teguhlab yum.repos.d]# df -kh
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda3       261G  3.0G  258G   2% /
devtmpfs        9.8G     0  9.8G   0% /dev
tmpfs           9.8G   84K  9.8G   1% /dev/shm
tmpfs           9.8G  9.0M  9.8G   1% /run
tmpfs           9.8G     0  9.8G   0% /sys/fs/cgroup
/dev/sda1       187M  146M   42M  78% /boot
tmpfs           2.0G   20K  2.0G   1% /run/user/0
/dev/sr0        3.6G  3.6G     0 100% /run/media/root/RHEL-7.3 Server.x86_64
[root@teguhlab yum.repos.d]#

.::: Troubleshoot MySQL is not running, but lock file (/var/lock/subsys/mysql[FAILED] :::.

1. Problem MySQL cannot start & tried restart
[root@TeguhLab ~]# service mysql status
MySQL is not running, but lock file (/var/lock/subsys/mysql[FAILED]
[root@TeguhLab ~]# service mysql restart
MySQL server PID file could not be found!                  [FAILED]
Starting MySQL.The server quit without updating PID file (/[FAILED]mysql/TeguhLab.pid).
[root@TeguhLab ~]#

result "MySQL is not running, but lock file (/var/lock/subsys/mysql[FAILED]"