postgresql - django.db.utils.OperationalError: could not connect to server: Connection refused

postgresql - django.db.utils.OperationalError: could not connect to server: Connection refused

Is the server running on host "host_name" (XX.XX.XX.XX) 
and accepting TCP/IP connections on port 5432?

尝试设置数据库服务器时的典型错误消息。但我无法修复它。

我的 Django 数据库设置:

DATABASES = {
   'default': {
      'ENGINE': 'django.db.backends.postgresql',
      'NAME': 'db_name',
      'USER': 'db_user',
      'PASSWORD': 'db_pwd',
      'HOST': 'host_name',
      'PORT': '5432',
   }
}

我添加到pg_hba.conf

host    all             all              0.0.0.0/0                       md5
host    all             all              ::/0                            md5

我在postgresql.conf中替换了:

listen_addresses = 'localhost'listen_addresses = '*'

并重新启动 postgresql:

/etc/init.d/postgresql stop
/etc/init.d/postgresql start

但仍然出现同样的错误。有趣的是:

我可以从外部 ping XX.XX.XX.XX 并且它有效。但我无法远程登录:

telnet XX.XX.XX.XX

Trying XX.XX.XX.XX...
telnet: connect to address XX.XX.XX.XX: Connection refused
telnet: Unable to connect to remote host

如果我从外部远程登录端口 22,它会工作:

telnet XX.XX.XX.XX 22

Trying XX.XX.XX.XX...
Connected to server_name.
Escape character is '^]'.
SSH-2.0-OpenSSH_6.7p1 Debian-5+deb8u3

如果我从数据库服务器内部远程登录端口 5432,我会得到:

telnet XX.XX.XX.XX 5432

Trying XX.XX.XX.XX...
Connected to XX.XX.XX.XX.
Escape character is '^]'.

来自外部的相同端口:

telnet XX.XX.XX.XX 5432

Trying XX.XX.XX.XX...
telnet: connect to address XX.XX.XX.XX: Connection refused
telnet: Unable to connect to remote host

nmap 来自内部:

Host is up (0.000020s latency).
Not shown: 998 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
5432/tcp open  postgresql

来自外部的 nmap:

Starting Nmap 7.60 ( https://nmap.org ) at 2018-01-24 07:01 CET

没有回应。

听起来像是防火墙问题,但我不知道去哪里找。我做错了什么,可能是什么问题?

感谢任何帮助。

顺便说一句:我可以在服务器内登录到 postgresql,它有效:

psql -h host_name -U user_name -d db_name

psql (9.4.15)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

db_name => 

正如我猜测的那样,问题是防火墙阻止了这些端口。我试图与托管公司沟通,但最后我不得不将服务器更改为其他托管公司,并且它使用确切的设置