Tunneling with DreamCompute

These steps set up remote access to a home network using an ssh tunnel to a DreamCompute host.

1. At the DreamCompute Security Groups and Key Pairs panels…
   1. Create a new Security Group ruleset. Add rules to open the desired ports, including port 22 for ssh and some random port (say, 1234) for remote access to the home server. For example, to open port 22 use parameters: Custom TCP Rule, Ingress, Port 22, Remote CIDR = 0.0.0.0/0.
   2. Create a Key Pair, download the private key (e.g., cloud.pem), and put it in the home server ~/.ssh directory.
2. At the DreamCompute Instances panel, launch a new instance (Boot Source Image Ubuntu 16.04, Flavor gp1.subsonic), selecting the newly created Security Group and Key Pair.
3. Create an A-type DNS record for the DreamCompute IP address with a name like casa.example.com. (Alternative: Use duckdns.org to create a public domain name.)
4. Using ssh from home machine, connect to Dreamhost instance (e.g., ssh -i .ssh/cloud.pem ubuntu@casa.example.com). Edit /etc/ssh/sshd_config and add this configuration information at the end (assuming default user is ubuntu):

   ClientAliveInterval 30
   ClientAliveCountMax 3
   
   Match User ubuntu
       GatewayPorts yes

   This step also ensures that the Dreamhost instance is added to the local ~/.ssh/known_hosts file.

5. While connected to the Dreamhost instance, do sudo apt-get and update, upgrade, dist-upgrade, and autoremove. And, reboot.
6. On home server, create a ~/.ssh/config file with something like this (assuming home server has local IP address 192.168.1.192 and is listening on ssh port 1234)…

   Host tunnel
   HostName casa.example.com
   User ubuntu
   IdentityFile ~/.ssh/cloud.pem
   BatchMode yes
   EscapeChar none
   RemoteForward *:1234 192.168.1.192:1234

7. Add this line to crontab:

   @reboot autossh -fN tunnel

8. From laptop (or other remote machine that has a private key paired with a home server public key in the authorized_keys file), use this instruction to remote ssh to account local:

   ssh local@casa.example.com -p 1234

1. DreamCompute instance
2. sshd_config manpage
3. autossh manpage