我正在尝试从我的家用电脑将 MariaDB 客户端（DBeaver）连接到我的数据库。 IP 地址/主机、端口、用户名和密码连接详细信息均正确。

我能够 ping 通主机。楼主活跃。我可以在服务器本地访问数据库。我已经为这种情况设置了 phpMyAdmin。但是，为了在不同的 VPS 上运行的游戏服务器，我需要能够进行外部连接。

这是我的 /etc/mysql/my.cnf 文件：

[client-server]
# Port or socket location where to connect
# port = 3306
socket = /run/mysqld/mysqld.sock

# Import all .cnf files from configuration directory
!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mariadb.conf.d/
[mysqld]
log_warnings=1
innodb_file_per_table = ON

此外，这是我的 50-server.cnf 文件：

#
# These groups are read by MariaDB server.
# Use it for options that only the server (but not clients) should see

# this is read by the standalone daemon and embedded servers
[server]

# this is only for the mysqld standalone daemon
[mysqld]

#
# * Basic Settings
#

user                    = mysql
pid-file                = /run/mysqld/mysqld.pid
basedir                 = /usr
datadir                 = /var/lib/mysql
tmpdir                  = /tmp
lc-messages-dir         = /usr/share/mysql
lc-messages             = en_US
skip-external-locking

# Broken reverse DNS slows down connections considerably and name resolve is
# safe to skip if there are no "host by domain name" access grants
#skip-name-resolve

# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address            = 0.0.0.0

#
# * Fine Tuning
#

#key_buffer_size        = 128M
#max_allowed_packet     = 1G
#thread_stack           = 192K
#thread_cache_size      = 8
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
#myisam_recover_options = BACKUP
#max_connections        = 100
#table_cache            = 64

#
# * Logging and Replication
#

# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# Recommend only changing this at runtime for short testing periods if needed!
#general_log_file       = /var/log/mysql/mysql.log
#general_log            = 1

# When running under systemd, error logging goes via stdout/stderr to journald
# and when running legacy init error logging goes to syslog due to
# /etc/mysql/conf.d/mariadb.conf.d/50-mysqld_safe.cnf
# Enable this if you want to have error logging into a separate file
#log_error = /var/log/mysql/error.log
# Enable the slow query log to see queries with especially long duration
#slow_query_log_file    = /var/log/mysql/mariadb-slow.log
#long_query_time        = 10
#log_slow_verbosity     = query_plan,explain
#log-queries-not-using-indexes
#min_examined_row_limit = 1000

# The following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see README.Debian about
#       other settings you may need to change.
#server-id              = 1
#log_bin                = /var/log/mysql/mysql-bin.log
expire_logs_days        = 10
#max_binlog_size        = 100M

#
# * SSL/TLS
#

# For documentation, please read
# https://mariadb.com/kb/en/securing-connections-for-client-and-server/
#ssl-ca = /etc/mysql/cacert.pem
#ssl-cert = /etc/mysql/server-cert.pem
#ssl-key = /etc/mysql/server-key.pem
#require-secure-transport = on

#
# * Character sets
#

# MySQL/MariaDB default is Latin1, but in Debian we rather default to the full
# utf8 4-byte character set. See also client.cnf
character-set-server  = utf8mb4
collation-server      = utf8mb4_general_ci

#
# * InnoDB
#

# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
# Most important is to give InnoDB 80 % of the system RAM for buffer use:
# https://mariadb.com/kb/en/innodb-system-variables/#innodb_buffer_pool_size
#innodb_buffer_pool_size = 8G

# this is only for embedded server
[embedded]

# This group is only read by MariaDB servers, not by MySQL.
# If you use the same .cnf file for MySQL and MariaDB,
# you can put MariaDB-only options here
[mariadb]

# This group is only read by MariaDB-10.5 servers.
# If you use the same .cnf file for MariaDB of different versions,
# use this group for options that older servers don't understand
[mariadb-10.5]

我浏览了一下并编辑了我的 /etc/mysql/mariadb.conf.d/50-server.cnf 文件，这样 绑定地址 = 0.0.0.0

我还创建了一个新用户，并使用 GRANT OPTION 将其主机设置为“%”，以确保允许该用户从外部 IP 进行访问。

仍然无法连接到数据库。

sudo iptables -L 返回：

Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ufw-before-logging-input  all  --  anywhere             anywhere
ufw-before-input  all  --  anywhere             anywhere
ufw-after-input  all  --  anywhere             anywhere
ufw-after-logging-input  all  --  anywhere             anywhere
ufw-reject-input  all  --  anywhere             anywhere
ufw-track-input  all  --  anywhere             anywhere
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:3306

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
ufw-before-logging-forward  all  --  anywhere             anywhere
ufw-before-forward  all  --  anywhere             anywhere
ufw-after-forward  all  --  anywhere             anywhere
ufw-after-logging-forward  all  --  anywhere             anywhere
ufw-reject-forward  all  --  anywhere             anywhere
ufw-track-forward  all  --  anywhere             anywhere

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
ufw-before-logging-output  all  --  anywhere             anywhere
ufw-before-output  all  --  anywhere             anywhere
ufw-after-output  all  --  anywhere             anywhere
ufw-after-logging-output  all  --  anywhere             anywhere
ufw-reject-output  all  --  anywhere             anywhere
ufw-track-output  all  --  anywhere             anywhere

Chain ufw-after-forward (1 references)
target     prot opt source               destination

Chain ufw-after-input (1 references)
target     prot opt source               destination

Chain ufw-after-logging-forward (1 references)
target     prot opt source               destination

Chain ufw-after-logging-input (1 references)
target     prot opt source               destination

Chain ufw-after-logging-output (1 references)
target     prot opt source               destination

Chain ufw-after-output (1 references)
target     prot opt source               destination

Chain ufw-before-forward (1 references)
target     prot opt source               destination

Chain ufw-before-input (1 references)
target     prot opt source               destination

Chain ufw-before-logging-forward (1 references)
target     prot opt source               destination

Chain ufw-before-logging-input (1 references)
target     prot opt source               destination

Chain ufw-before-logging-output (1 references)
target     prot opt source               destination

Chain ufw-before-output (1 references)
target     prot opt source               destination

Chain ufw-reject-forward (1 references)
target     prot opt source               destination

Chain ufw-reject-input (1 references)
target     prot opt source               destination

Chain ufw-reject-output (1 references)
target     prot opt source               destination

Chain ufw-track-forward (1 references)
target     prot opt source               destination

Chain ufw-track-input (1 references)
target     prot opt source               destination

Chain ufw-track-output (1 references)
target     prot opt source               destination

据我所知，没有防火墙。我当前正在尝试从本地环境连接到数据库，该环境具有动态 IP。我计划仅在达到这一点后才允许从其他 VPS IP 进行设置。

UFW 未安装，根据我尝试过的评论：sudo ufw status

当我尝试从桌面连接时，出现的问题是超时问题。就好像服务器没有读取/接受来自我的 IP 的传入连接。

我还使用 portchecker.co 检查端口 3306 的服务器 IP，它返回为 Closed，尽管上面显示它正在监听。

当尝试连接 HeidiSQL 时，出现错误：无法连接到“1.2.3.4”上的服务器 (10060) 当然，1.2.3.4 已替换为我服务器的 IP。

检查 netstat -tlnp | grep 3306 - 它返回： tcp 0 0 0.0.0.0:3306 0.0.0.0:* 监听 3900555/mariadbd