CentOS 7 關閉IPv6

1、編輯/etc/default/grub

編輯/etc/default/grub，在GRUB_CMDLINE_LINUX加上的後面句首加上ipv6.disable=1。 

修改以前：

[root@CentOS74-02 ~]# cat /etc/default/grub 

GRUB_TIMEOUT=5

GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"

GRUB_DEFAULT=saved

GRUB_DISABLE_SUBMENU=true

GRUB_TERMINAL_OUTPUT="console"

GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb quiet"

GRUB_DISABLE_RECOVERY="true"

修改以後：

[root@CentOS74-02 ~]# cat /etc/default/grub 

GRUB_TIMEOUT=5

GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"

GRUB_DEFAULT=saved

GRUB_DISABLE_SUBMENU=true

GRUB_TERMINAL_OUTPUT="console"

GRUB_CMDLINE_LINUX="ipv6.disable=1 crashkernel=auto rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb quiet"

GRUB_DISABLE_RECOVERY="true"

2、從新生成grub.cfg文件

修改完畢後保存，運行grub2-mkconfig -o /boot/grub2/grub.cfg從新生成grub.cfg文件。

[root@CentOS74-02 ~]# grub2-mkconfig -o /boot/grub2/grub.cfg 

Generating grub configuration file ...

Found linux image: /boot/vmlinuz-3.10.0-514.2.2.el7.x86_64

Found initrd image: /boot/initramfs-3.10.0-514.2.2.el7.x86_64.img

Found linux image: /boot/vmlinuz-3.10.0-327.36.3.el7.x86_64

Found initrd image: /boot/initramfs-3.10.0-327.36.3.el7.x86_64.img

Found linux image: /boot/vmlinuz-3.10.0-327.el7.x86_64

Found initrd image: /boot/initramfs-3.10.0-327.el7.x86_64.img

Found linux image: /boot/vmlinuz-0-rescue-d885883cdb4944609bc5e3493dd2b680

Found initrd image: /boot/initramfs-0-rescue-d885883cdb4944609bc5e3493dd2b680.img

done

3、重啓系統

運行下面的命令，已經看不到tcp6的協議：

[root@CentOS74-02 ~]# netstat -nltp

Active Internet connections (only servers)

Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    

tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1030/sshd           

tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      1294/master         

[root@CentOS74-02 ~]#