MySQL server unreachable on some server, but not all server,e.g.
MySQL server on server A(linode)
web server 1 on server B(home hosted, port not blocked)
web server 2 on server B(home hosted, port not blocked)
web server 1 on server C(digital ocean)
now my web server 1 on server B can connect to MySQL, but web server 2 on server B and web server 1 on server C can't(same user same database), what can cause this?and how to fix this problem?