解決：etwork unreachable resolving問題

系統： CentOS Linux release 7.7.1908 (Core)
bind: BIND 9.11.4-P2-RedHat-9.11.4-16.P2.el7_8.6

部署使用bind後， 使用systemctl status named或者查看messages日誌，都能看到
Jul 12 06:08:40 od-bind-81 named[994]: network unreachable resolving 'gateway/A/IN': 2001:500:12::d0d#53
Jul 12 06:08:40 od-bind-81 named[994]: network unreachable resolving 'gateway/A/IN': 2001:500:2::c#53
Jul 12 06:08:40 od-bind-81 named[994]: network unreachable resolving 'gateway/A/IN': 2001:dc3::35#53
的報錯信息，
緣由：named嘗試使用IPV6進行傳輸
因此讓named只運行在IPV4模式下：
cat >> /etc/sysconfig/named <<EOF
OPTIONS="-4"
EOF

檢查一下是否已經添加：
cat /etc/sysconfig/named

重啓named
systemctl restart named

查看運行狀況
systemctl status named

就沒有報錯信息了