SSH tunnel: local => gateway => MySQL server

Question

I need to access a MySQL database on a remote server at my lab. The server is only accessible once I log in to a gateway server on the remote network:

local serv         


        

Answer 1

With the command:

$ ssh -f user@gateway -L 3307:1.2.3.4:3306 -N 

This states that all connections to client localhost 3307 will be forwarded via the SSH tunnel to gateway and then connected to host 1.2.3.4 to port 3306.

edit: If the SSH is on port 24222 then

$ ssh -f user@gateway -p 24222 -L 3307:1.2.3.4:3306 -N 

Answer 2

Using the tunnel:

ssh -f user@gateway -L 3307:1.2.3.4:3306 -N 

you will be able to connect to the database on localhost port 3307

Answer 3

If You need to use multiple hops to access MySQL server I first recommend to create .ssh/config file and use ProxyCommand like so:

  Host gateway
     HostName example.com
     User foo
     Port 22
     IdentityFile ~/.ssh/id_rsa.pub

  Host mysql_access_server
      HostName example-web.com
      Port 22
      User foo
      ProxyCommand ssh -A gateway nc %h %p

Then forward port like so:

ssh -f mysql_access_server -L 3309:sqlmaster.example.com:3306 -N

Then You can access MySQL server like so:

mysql --user=root --host=127.0.0.1 --password=root --port=3309 some_db_name