unknown hostname

sorry if i did not make myself clear enough.
i am able to ssh from machine with ip address 128.153.144.233 BUT not to it.
In another 128.153.144.233 seems unknown from outside.

either your SSH Daemon isn't running on that machine or your firewall settings are blocking port 22.

I am going to assume this is a box on a cable modem. If this is the case you need a dynamic DNS client (www.dyndns.org) to one make the machine accessible from the Internet. Two as mentioned above  by rindi you need to make sure if you have a router in front of the box that it allows SSH connections through from the Internet. Then you should be all set because all default SSH installs will allow connections from 0.0.0.0/24 (i.e anywhere). Hope this helps.

Cheers,
John

I need to ammend my above statement: "If this is the case you need a dynamic DNS client (www.dyndns.org) to one make the machine accessible from the Internet" It should read "If this is the case you need a dynamic DNS client (www.dyndns.org) to one make the machine accessible from the Internet by hostname otherwise you can continue to access by IP, provided your IP does not change.

John