How to disable IPv6 on CentOS 7

To verify if IPv6 is enabled or not, execute :

# ifconfig -a | grep inet6
inet6 fe80::211:aff:fe6a:9de4 prefixlen 64 scopeid 0x20
inet6 ::1 prefixlen 128 scopeid 0x10[host]

1. Disable IPv6 in kernel module (requires reboot)
1. Edit /etc/default/grub and add ipv6.disable=1 in line GRUB_CMDLINE_LINUX, e.g.:

# cat /etc/default/grub
GRUB_TIMEOUT=5
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="ipv6.disable=1 crashkernel=auto rhgb quiet"
GRUB_DISABLE_RECOVERY="true"

2. Regenerate a GRUB configuration file and overwrite existing one:

# grub2-mkconfig -o /boot/grub2/grub.cfg

3. Restart system and verify no line “inet6” in “ip addr show” command output.

# shutdown -r now

# ip addr show | grep net6
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How To Change SSH Port On CentOS 7

To change the default SSH port, the first thing you want to do is backup the current SSH configuration on your system. To do that, run the commands below.

cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak

Next, run the commands below to open the default SSH configuration file

sudo vi /etc/ssh/sshd_config

# If you want to change the port on a SELinux system, you have to tell
# SELinux about this change.
# semanage port -a -t ssh_port_t -p tcp #PORTNUMBER
#
Port 2244
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::

Save the file.

After saving, don’t exit until you’ve completed these steps.
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Turut Prihatin Atas Musibah Gempa dan Tsunami Palu dan Donggala

Whplus menyampaikan turut prihatin dan duka cita atas musibah gempa dan tsunami yang terjadi di Palu dan Donggala Sulawesi Tengah. Semoga masyarakat di Palu, Donggala dan sekitarnya selalu dalam lindunganNYA dan bersabar atas musibah ini.

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