What network type are you using for the guest. It will need to be "Bridged" to be able to access it from outside your host. After you have that set up, it should behave (for networking purposes) exactly like a physical host on your network.
This might, however, not work with your direct connection to the modem.
The network connection is set up as bridged. I run lsof -i on the centos and use the port listed as listening for ssh when trying to connect remotely.
For example, centos says port 11213 is used to listen for SSH connections, so when I try to remote SSH I type remote.ip.address.here and port 11213. Still says connection refused.
ps- Im using putty as my SSH connection client.
Now it tells me when trying to connect:
"Server unexpectdedly closed connection"
Ive tried direct connecting to the open port on vm for ssh, and Ive also tried port tunneling via putty from an open port on the host machine to the ssh port on vm.
This is really getting aggrivating.
You will need to enable ssh for external networks.
Open /etc/hosts.allow ( something like $vi /etc/hosts.allow) and add the following line at the bottom:
or even easier type at the prompt
echo "SSHD: ALL" >> /etc/hosts.allow
This will allow all external networks to connect to the SSH service.
otherwise you can put an IP or a range of IPs to have a more secure system (google hosts allow for more information).