防止“hostmaster”子域重定向到主站点

Question

我在一台装有 nginx/1.6.2 的 Debian 8 服务器上托管mainsite.com。othersite.net最近我发现 Google 已将其编入索引hostmaster.othersite.net，并且此子域显示了 的全部内容mainsite.com。

我在 DNS 查找工具中看到此子域名为SOA指向的记录[email protected]，但它不在主机提供商的控制面板中。它在哪里，我该如何删除此重定向？

DNS 记录：

CNAME | *.mainsite.com  | is an alias of mainsite.com.     | 1800
A     | mainsite.com    | directs to xx.xx.xx.xx           | 1800 
NS    | mainsite.com    | directs to ns1.digitalocean.com. | 1800 
NS    | mainsite.com    | directs to ns2.digitalocean.com. | 1800 
NS    | mainsite.com    | directs to ns3.digitalocean.com. | 1800 


CNAME | *.othersite.net | is an alias of othersite.net.    | 1800
A     | othersite.net   | directs to xx.xx.xx.xx           | 1800
NS    | othersite.net   | directs to ns3.digitalocean.com. | 1800
NS    | othersite.net   | directs to ns1.digitalocean.com. | 1800
NS    | othersite.net   | directs to ns2.digitalocean.com. | 1800

简化nginx.conf（仅location删除 www 重定向）：

server {
        listen 443 ssl default_server;

        ssl_certificate /etc/letsencrypt/live/mainsite.com/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/mainsite.com/privkey.pem;

        server_name mainsite.com;
        root /home/mainsite/html;
}

server {
        listen 80;
        server_name mainsite.com;
        return 301 https://mainsite.com$request_uri;
}

server {
        listen 443 ssl;

        ssl_certificate /etc/letsencrypt/live/othersite.net/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/othersite.net/privkey.pem;

        server_name othersite.net;
        root /home/othersite/html;
}

server {
        listen 80;
        server_name othersite.net;
        return 301 https://othersite.net$request_uri;
}