在OSX上设置caching forward-only的dns服务

以前在BSD和Linux下面一直用djbdns做dns本地缓存，用Mac之后用过一段时间的dnsmasq，djbdns比dnsmasq设置简单一些，dnsmasq配置了几次才成功。
最近重装系统后打算重新弄一个，不过这次是打算用系统自带的bind服务，不用安装编译，直接就是现成的。
bind我其实不熟悉，好在可以google到不少配置文件进行参考，只有一点经验可以说一下

named-checkconf /etc/named.conf

东抄西抄的配置文件难免会有问题，用这个命令检查一下配置文件是否正确，省得启动服务失败了再看日志调试

如果是通过已有的/etc/named.conf直接修改，会报一个rndc.key不存在的错误，用这个命令创建一下就好

rndc-confgen -a

最后把服务启动用

sudo launchctl load -w /System/Library/LaunchDaemons/org.isc.named.plist

再把dns指向127.0.0.1就搞定了

附上我的named.conf参考

//
// Include keys file
//
include "/etc/rndc.key";

// Declares control channels to be used by the rndc utility.
//
// It is recommended that 127.0.0.1 be the only address used.
// This also allows non-privileged users on the local host to manage
// your name server.

//
// Default controls
//
controls {
	inet 127.0.0.1 port 54 allow {any;}
	keys { "rndc-key"; };
};

options {
	directory "/var/named";
	/*
	 * If there is a firewall between you and nameservers you want
	 * to talk to, you might need to uncomment the query-source
	 * directive below.  Previous versions of BIND always asked
	 * questions using port 53, but BIND 8.1 uses an unprivileged
	 * port by default.
	 */
	// query-source address * port 53;

    listen-on { 127.0.0.1; };
    forwarders {
        8.8.8.8;
        208.67.222.222;
        208.67.220.220;
    };
    forward only;
    max-cache-size 2097152;
};
// 
// a caching only nameserver config
// 
zone "." IN {
	type hint;
	file "named.ca";
};

zone "localhost" IN {
	type master;
	file "localhost.zone";
	allow-update { none; };
};

zone "0.0.127.in-addr.arpa" IN {
	type master;
	file "named.local";
	allow-update { none; };
};

logging {
        category default {
                _default_log;
        };

        channel _default_log  {
                file "/Library/Logs/named.log";
                severity info;
                print-time yes;
        };
};