我在CentOS 6.6系统上安装了postgres-9.4数据库服务器。我正在尝试从我的笔记本电脑连接到此服务器（连接到同一网络。笔记本电脑的IP是192.168.1.105。我正在运行psql -U postgres -h 192.168.1.52）。 psql命令失败并显示错误消息：
psql -U postgres -h 192.168.1.52
could not connect to server: COnnection refused
Is the server running on host 192.168.1.52 and accepting TCP/IP connection on port 5432?
我的配置： /var/lib/pgsql/9.4/data/pg_hba.conf
# TYPE DATABASE USER ADDRESS METHOD
# "local" is for Unix domain socket connections only
local all all peer
# IPv4 local connections:
host all all 127.0.0.1/32 trust
host all all 192.168.0.0/16 trust
host all all 0.0.0.0/0 trust
# IPv6 local connections:
host all all ::1/128 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
#local replication postgres peer
#host replication postgres 127.0.0.1/32 ident
#host replication postgres ::1/128 ident
的/ etc / SYSCONFIG / iptables的：
# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
-A INPUT -m state --state NEW -m tcp -p tcp --dport 5432 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
COMMIT
我已经重新启动了iptables服务。
/var/lib/pgsql/9.4/data/postgresql.conf
listen_addresses = '*'
port = 5432
我重启服务器如下：
[root@cinch-database1 9.4]# service postgresql-9.4 restart
Stopping postgresql-9.4 service: [ OK ]
Starting postgresql-9.4 service: [ OK ]
ps aux和grep postgres返回以下内容：
ps auxwww | grep postgres
postgres 11460 0.0 0.0 325096 14860 ? S 01:36 0:00 /usr/pgsql-9.4/bin/postmaster -D /var/lib/pgsql/9.4/data
postgres 11463 0.0 0.0 180244 1264 ? Ss 01:36 0:00 postgres: logger process
postgres 11465 0.0 0.0 325096 1564 ? Ss 01:36 0:00 postgres: checkpointer process
postgres 11466 0.0 0.0 325096 2544 ? Ss 01:36 0:00 postgres: writer process
postgres 11467 0.0 0.0 325096 1496 ? Ss 01:36 0:00 postgres: wal writer process
postgres 11468 0.0 0.0 325508 2340 ? Ss 01:36 0:00 postgres: autovacuum launcher process
postgres 11469 0.0 0.0 180376 1476 ? Ss 01:36 0:00 postgres: stats collector process
root 11516 0.0 0.0 103252 844 pts/0 S+ 01:41 0:00 grep postgres
当我在服务器上执行netstat并且为5432执行grep时，我什么也得不到：
netstat | grep 5432
但netstat -tulnp会返回此信息：
tcp 0 0 0.0.0.0:5432 0.0.0.0:* LISTEN 13227/postmaster
输出'netstat -l | grep postgres'
[root@cinch-database1 pg_log]# netstat -l|grep postgres
tcp 0 0 *:postgres *:* LISTEN
tcp 0 0 *:postgres *:* LISTEN
但如前所述，我的笔记本电脑的psql无法连接到服务器。
我错过了什么？
答案 0 :(得分：1)
这是一个防火墙问题。我必须在序列中的前面的iptables文件中移动以下两行：
-A INPUT -m state --state NEW -m tcp -p tcp --dport 5432 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
新iptables：
# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 5432 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
在此之后我重启了iptables服务：
service iptables restart
现在我可以从笔记本电脑连接到postgres。
答案 1 :(得分：0)
防火墙似乎阻止了您的连接，因此只需尝试使用以下命令禁用防火墙：
sudo service iptables stop
然后如果通过，请正确设置。