Proxy server TCP_MISS/503 443 Problem [solved]

CentOS 7.2 Squid Proxy Server

/var/log/squid/access.log error message

TCP_MISS/503 0 CONNECT www.facebook.com:443 - HIER_NONE/- -
TCP_MISS/503 0 CONNECT www.google.co.kr:443 - HIER_NONE/- -

443 Port add
# firewall-cmd --permanent --zone=public --add-port=443/tcp
# firewall-cmd --reload

# vi /etc/sysctl.conf

net.ipv6.conf.all.disable_ipv6 = 1

net.ipv4.ip_forward = 1

# sysctl -p

reference url : http://blog.ivps.kr/25