April 2016
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April 2016
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11121314151617
18192021222324
252627282930  

Configuring Postfix as a Null Client

Configuring Postfix as a Null Client

This howto assumes that the relay server’s IP address is 192.168.1.22 and is running RHEL/CentOS 7. Only mail from the 192.168.1.0/24 network should be accepted and relayed.

Install Postfix [root@rhce-server ~]# yum install postfix

Configure Systemd [root@rhce-server ~]# systemctl enable postfix [root@rhce-server ~]# ^enable^start

Configure the Firewall [root@rhce-server ~]# […]

unbound RHCE

This howto shows the steps needed to configure unbound for DNS caching and forwarding from the 192.168.1.0/24 network. It assumes the server’s IP address is 192.168.1.22 and is running RHEL/CentOS 7.

Installation [root@rhce-server ~]# yum install unbound

Configure Systemd [root@rhce-server ~]# systemctl enable unbound ln -s ‘/usr/lib/systemd/system/unbound.service’ ‘/etc/systemd/system/multi-user.target.wants/unbound.service’ [root@rhce-server ~]# ^enable^start systemctl start unbound

Configure […]

rhel7 root user password cracking

Edit current kernel version into the grub menu bar, and finally add rd.break parameters linux6

linux16 /vmlinuz-3.10.0-327.el7.x86_64 root=/dev/mapper/rhel-root ro rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet rd.break Use ctrl + x to reboot the system to start

Remount the ‘root’ file system, and change into the / sysroot

mount -oremount,rw /sysroot chroot /sysroot Changing the root password

echo […]

Booting into single user mode and changing root password Centos / Redhat 7

During boot, press “e” at the grub loader. Scroll down using the arrow keys to the line starting with “linux”. It would look like this. linux16 /vmlinuz-3.10.0…… Remove the following from that line. “rhgb” and “quiet“. Add the following to the end of the line. “init=/bin/sh“. Press ctrl+x to continue the boot process. Once the […]