第二个子域名重定向到主域名，但 URL 仍然与第二个域名相同

Question

看到标题描述的这个问题，感觉很奇怪。具体如下：

1) 创建了带有“a1”的 A 记录。表示子域名为：a1.example.com，

2）通过创建目录"sudo nano /var/www/a1.example.com/html/"

3）创建服务器块"sudo nano /etc/nginx/sites-available/a1.example.com"

4）服务器块内部核心部分：

server {
listen 80;
listen [::]:80;

root /var/www/a1.example.com/html;
index index.html index.htm;

server_name a1.example.com

location / {
try_files $uri $uri/ =404;
}
}

5）创建链接：sudo ln -s /etc/nginx/sites-available/a1.example.com /etc/nginx/sites-enabled/

6）sudo nano /etc/nginx/nginx.conf，取消注释：server_names_hash_bucket_size 64;

确认：include /etc/nginx/sites-enabled/*;是否有

7）重新启动nginx：sudo service nginx restart

这样做之后，第一个子域名就可以a1.example.com正常工作了。

b2.example.com但当我尝试按照上述步骤创建第二个子域名时，b2.example.com却无法正常工作：它将重定向到主页，但 URL 仍然保持为b2.example.com

有什么问题呢？

非常感谢！

---

配置a1.example.com

server {
    listen 80;
    listen [::]:80;

    root /var/www/a1.example.com/html;
    index index.php index.html index.htm;

    server_name a1.example.com;

    rewrite ^/archives/(\d+)$ http://a1.example.com/?p=$1 permanent;

    location / {
        try_files $uri $uri/ /index.php?q=$uri&args;
    }

    error_page 404 /404.html;
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }

    location ~ \.php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass unix:/var/run/php5-fpm.sock;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;

    }

}

配置b2.example.com

server {
    listen 80;
    listen [::]:80;

    root /var/www/b2.example.com/html;
    index index.php index.html index.htm;

    server_name b2.example.com;

    rewrite ^/archives/(\d+)$ http://b2.example.com/?p=$1 permanent;

    location / {
        try_files $uri $uri/ /index.php?q=$uri&args;

    }

    error_page 404 /404.html;
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }

    location ~ \.php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass unix:/var/run/php5-fpm.sock;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;

    }

}

---

curl -I b2.example.com:
HTTP/1.1 200 OK
Server: nginx/1.8.1
Date: Thu, 04 Feb 2016 05:54:22 GMT
Content-Type: text/html; charset=UTF-8
Connection: keep-alive
X-Powered-By: PHP/5.5.9-1ubuntu4.14
Set-Cookie: PHPSESSID=4r143k0o1m1l62p3g4vt1jrav1; path=/
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Link: <http://www.example.com/wp-json/>; rel="https://api.w.org/"
Link: <http://www.example.com/>; rel=shortlink

curl -I a1.example.com
HTTP/1.1 200 OK
Server: nginx/1.8.1
Date: Thu, 04 Feb 2016 05:54:32 GMT
Content-Type: text/html; charset=UTF-8
Connection: keep-alive
X-Powered-By: PHP/5.5.9-1ubuntu4.14
Link: <http://a1.example.com/wp-json/>; rel="https://api.w.org/"