failure in connecting to my server through ssh

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http://unix.stackexchange.com – My goal: I want to be able to ssh to my workstation from external client. My workstation(in the following also referred as server) is on a lan. Its ip address on this lan is obviously different from its ip on the internet. I have set up the ssh server with public keys. This is what happens when I try to ssh from a client: If the client is on the same lan: I try to ping my server using the ip returned by ifconfig. The client cannot ping my server. If the client is from outside, not on the lan: The client can ping the server, but when I try to connect I get Connection timed out (HowTos)