[named] option 'allow-update' is not allowed in 'slave'

The start-up result is done.
Jul 30 04:50:46 n1 systemd[1]: Starting Berkeley Internet Name Domain (DNS)...
-- Subject: Unit named.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit named.service has begun starting up.
Jul 30 04:50:46 hostname bash[27858]: /etc/named.rfc1912.zones:47: option 'allow-update' is not allowed in 'slave' zone 'exmple.domain'
Jul 30 04:50:46 hostname systemd[1]: named.service: control process exited, code=exited status=1
Jul 30 04:50:46 n1 systemd[1]: Failed to start Berkeley Internet Name Domain (DNS).
-- Subject: Unit named.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit named.service has failed.
--
-- The result is failed.
Jul 30 04:50:46 hostname systemd[1]: Unit named.service entered failed state.
Jul 30 04:50:46 hostname systemd[1]: named.service failed.
Jul 30 04:50:46 hostname polkitd[13650]: Unregistered Authentication Agent for unix-process:27841:321261635 (system bus name :1.49824, object path /org/freedesktop
Jul 30 04:50:49 hostname dhclient[934]: PRC: Renewing lease on eth0.
Jul 30 04:50:49 hostname dhclient[934]: XMT: Renew on eth0, interval 10800ms.
Jul 30 04:50:49 hostname dhclient[934]: RCV: Reply message on eth0 from fe80::69:beff:fe21:ea3a.

(1) 까닭

  /etc/named.rfc1912.zones 파일의 영역(zone) 설정 내용에 종속(슬레이브) 서버로 설정했는데, 주(마스터) 서버에 들어가야 할 'allow-update' 항목이 들어갔기 때문.

(2) 풀기

  종속(슬레이브) 서버의 /etc/named.rfc1912.zones 파일의 영역(zone) 설정 내용에서

zone "example.domain" IN {
	type slave;
	file "example.domain.zone";
	masters { 111.111.111.100; };
	allow-notify { 111.111.111.100; };
	allow-update { 222.222.222.200; };
};

↓

zone "example.domain" IN {
	type slave;
	file "example.domain.zone";
	masters { 111.111.111.100; };
	allow-notify { 111.111.111.100; };
};

allow-update 항목을 지우고 named를 다시 시작한다.