Acess Intranet without VPN

Sometimes I need access the Intranet of company, however I don't like to create VPN connection. The connection is slow, waste time to create the connection and have to change password due to security policy.

My workstation is Linux, which has a lot of utility tools to help me access Intranet at home without VPN.

Firstly I set up a ssh server on my personal computer. It's quite easy if you are using Linux, for Windows I installed Copssh.
Then register a free domain name and configure it in my router. And let router forward port 22(or any port you wan to use) to my personal computer.
In my working Linux machine, create a ssh tunnel to my personal computer. Must use the public/private key for authenticating. For example,

It means remote server can access my workstation's port 22 via accessing its port 1002 after the ssh tunnel is created successfully. Above command line also forwards the ports 5900 and 6500. The default VNC session will listen the port 5900.
But it only works when my personal computer is running. And the connection can't be reconnected after it fails once.
The graceful solution is installing 'autossh' in my Linux, which is an utility to retry the ssh connection with an interval if it's disconnected or failed.

 Then create a script and running it when OS is booted. The script will be executed by root user, so we need configure it ran by the normal user.

After my personal computer is booted a while(the default interval of autossh is 300 seconds), I can use localhost:10002 to login my workstation, localhost:5900 to access my VNC session. Of course you can use 'froxyproxy' of Firefox via a localport to access web page of Intranet.

[tip]ssh key

Setup SSH without password.
a) execute "ssh-keygen -t rsa" under your linux/unix login to get the RSA keys.
(press Enter for all)
You will get 2 files uner ~/.ssh/, id_rsa and id_rsa.pub
b) Put the public key id_rsa.pub to your remote host: ~/.ssh/authorized_keys If the remote host share the same nfs, just try " cat id_rsa.pub >> ~/.ssh/authorized_keys"
* Remember to modify hostname or ip info in ~/.ssh/authorized_keys to "*", so that you can login from any host without password in your NIS domain.
For example:
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA4Ri5J0s1BL/+mR7RfAuDW6FY2P6ILc61Zvw1BdDkvHMFrTzaC/AUMw33H7biAMCXuCleakCuSoV8ZDiGHYs4wOVvet5sDmphkwdiC4xTekdl3dRNvGjMVbvFUta/Y5CiayL6YIu47Ro6Vvu4Mutsrv/13pTlifrEz+NTR/+bzMb9nTniCwiryMyYod3E46b8WvS8yE3WK+tH4BZE8bjiCwdvAzSdPyk/OFNrlBNuF1yewwnxv1roRD3UalT2+7O4kfEG9sMvvBHjuX2l7xlUe3stBftYpigBbwGmmadxjRpNIlk88t5xKcQX6nSu7V8HI3GWPHI0D+ISIlbfU5Sunw== kzhu0@*

[tip]ssh forward

ssh -qTfnN -D LocalPort remotehost

All the added options are for a ssh session that's used for tunneling.

-q :- be very quite, we are acting only as a tunnel.
-T :- Do not allocate a pseudo tty, we are only acting a tunnel.
-f :- move the ssh process to background, as we don't want to interact with this ssh session directly.
-N :- Do not execute remote command.
-n :- redirect standard input to /dev/null.

In addition on a slow line you can gain performance by enabling compression with the -C option.