我在VPS上部署了nodejs应用程序，但是它无法连接到另一台服务器上托管的MySQL数据库，但可以在我的PC和另一台VPS上运行。
我决定对此进行测试：
nmap -p 3306 mysqlserver.com
PORT STATE SERVICE
3306/tcp filtered mysql
当我在个人计算机上尝试时，我得到了：
nmap -p 3306 mysqlserver.com
PORT STATE SERVICE
3306/tcp open mysql
我可以成功连接到PC上的远程mysql
iptables
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1226/sshd
tcp 0 0 0.0.0.0:5432 0.0.0.0:* LISTEN 1282/postgres
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1543/master
tcp6 0 0 :::48937 :::* LISTEN 2572/node
tcp6 0 0 :::80 :::* LISTEN 1229/httpd
tcp6 0 0 :::22 :::* LISTEN 1226/sshd
tcp6 0 0 :::5432 :::* LISTEN 1282/postgres
tcp6 0 0 ::1:25 :::* LISTEN 1543/master
tcp6 0 0 :::47135 :::* LISTEN 2572/node
udp 0 0 0.0.0.0:5353 0.0.0.0:* 604/avahi-daemon: r
udp 0 0 0.0.0.0:54701 0.0.0.0:* 604/avahi-daemon: r
[root@host1 /]# iptables -L -n -v
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3306
84363 8756K ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
3 180 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0
8791 554K INPUT_direct all -- * * 0.0.0.0/0 0.0.0.0/0
8791 554K INPUT_ZONES_SOURCE all -- * * 0.0.0.0/0 0.0.0.0/0
8791 554K INPUT_ZONES all -- * * 0.0.0.0/0 0.0.0.0/0
1163 41912 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0
405 79341 REJECT all -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp spt:3306
0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 udp spt:3306 dpt:3306
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp spt:3306 ctstate ESTABLISHED
0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3306 state NEW,ESTABLISHED
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0
0 0 FORWARD_direct all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 FORWARD_IN_ZONES_SOURCE all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 FORWARD_IN_ZONES all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 FORWARD_OUT_ZONES_SOURCE all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 FORWARD_OUT_ZONES all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0
0 0 REJECT all -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT 9878 packets, 1240K bytes)
pkts bytes target prot opt in out source destination
72617 11M OUTPUT_direct all -- * * 0.0.0.0/0 0.0.0.0/0
14 616 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3306
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3306
0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp spt:3306 state ESTABLISHED
Chain FORWARD_IN_ZONES (1 references)
pkts bytes target prot opt in out source destination
0 0 FWDI_public all -- ens160 * 0.0.0.0/0 0.0.0.0/0 [goto]
0 0 FWDI_public all -- + * 0.0.0.0/0 0.0.0.0/0 [goto]
Chain FORWARD_IN_ZONES_SOURCE (1 references)
pkts bytes target prot opt in out source destination
Chain FORWARD_OUT_ZONES (1 references)
pkts bytes target prot opt in out source destination
0 0 FWDO_public all -- * ens160 0.0.0.0/0 0.0.0.0/0 [goto]
0 0 FWDO_public all -- * + 0.0.0.0/0 0.0.0.0/0 [goto]
Chain FORWARD_OUT_ZONES_SOURCE (1 references)
pkts bytes target prot opt in out source destination
Chain FORWARD_direct (1 references)
pkts bytes target prot opt in out source destination
Chain FWDI_public (2 references)
pkts bytes target prot opt in out source destination
0 0 FWDI_public_log all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 FWDI_public_deny all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 FWDI_public_allow all -- * * 0.0.0.0/0 0.0.0.0/0
Chain FWDI_public_allow (1 references)
pkts bytes target prot opt in out source destination
Chain FWDI_public_deny (1 references)
pkts bytes target prot opt in out source destination
Chain FWDI_public_log (1 references)
pkts bytes target prot opt in out source destination
Chain FWDO_public (2 references)
pkts bytes target prot opt in out source destination
0 0 FWDO_public_log all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 FWDO_public_deny all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 FWDO_public_allow all -- * * 0.0.0.0/0 0.0.0.0/0
Chain FWDO_public_allow (1 references)
pkts bytes target prot opt in out source destination
Chain FWDO_public_deny (1 references)
pkts bytes target prot opt in out source destination
Chain FWDO_public_log (1 references)
pkts bytes target prot opt in out source destination
Chain INPUT_ZONES (1 references)
pkts bytes target prot opt in out source destination
8791 554K IN_public all -- ens160 * 0.0.0.0/0 0.0.0.0/0 [goto]
0 0 IN_public all -- + * 0.0.0.0/0 0.0.0.0/0 [goto]
Chain INPUT_ZONES_SOURCE (1 references)
pkts bytes target prot opt in out source destination
Chain INPUT_direct (1 references)
pkts bytes target prot opt in out source destination
Chain IN_public (2 references)
pkts bytes target prot opt in out source destination
8791 554K IN_public_log all -- * * 0.0.0.0/0 0.0.0.0/0
8791 554K IN_public_deny all -- * * 0.0.0.0/0 0.0.0.0/0
8791 554K IN_public_allow all -- * * 0.0.0.0/0 0.0.0.0/0
Chain IN_public_allow (1 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:21 ctstate NEW
230 13572 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 ctstate NEW
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3306 ctstate NEW
25 1120 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 ctstate NEW
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:5025 ctstate NEW
6968 418K ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:5432 ctstate NEW
0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 udp dpt:80 ctstate NEW
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3306 ctstate NEW
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3001 ctstate NEW
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3030 ctstate NEW
Chain IN_public_deny (1 references)
pkts bytes target prot opt in out source destination
Chain IN_public_log (1 references)
pkts bytes target prot opt in out source destination
Chain OUTPUT_direct (1 references)
pkts bytes target prot opt in out source destination
我需要在我的VPS中请求mysqlserver.com：3306
这被防火墙阻止了吗？
我正在mysql访问主机列表中使用％
Node JS连接
var db_config = {
host: "mysqlserver.com",
port: 3306,
user: "user",
password: "pass",
database: "database",
};
我尝试请求另一台服务器，但我获得了“打开”
nmap -p 3306 myOtherHosting.com
PORT STATE SERVICE
3306/tcp open mysql