[CentOS7] How to disable IPv6 in CentOS7 (CentOS7 IPv6 비활성화)

I ran UDP socket program using 61000 port. But, only IPv6 socket was activating.

How to disable IPv6?

1. Add options in sysctl.conf

#> vi /etc/sysctl.conf

# for diable ipv6
net.ipv6.conf.all.disable_ipv6 = 1

# for diable paricular adapter
#net.ipv6.conf.eth0.disable_ipv6 = 1

2. Apply options

#> sysctl -p

3. Restart Socket program