scp vs rcp - password question

Do you have a question? Post it now! No Registration Necessary.  Now with pictures!

Threaded View
In the SSH book by O'Reilly, it seems to suggest that scp is just rcp over
SSH and scp is intended to replace rcp with the least change.

I don't understand how scp can replace rcp. In Unix, which I think it is
where ssh was invented, rcp can copy file without specifying password. The
rcp server verifies the host and user_id in the .rhosts file and decide to
allow or disallow a copy. But when I use scp, it always ask me for password.

Suppose I have a bunch of scripts using rcp. What do I need to do besides
the single character change from "rcp" to "scp"? I tried copying server's
.rhosts to .shosts but that makes no difference.

I just started learning ssh so please use plain language... :)

Re: scp vs rcp - password question

John Smith wrote:
Quoted text here. Click to load it

SSH can use user keys, host keys, or .shosts type password-less
authentication. I'd recommend using user keys for small groups and host
based keys for larger groups. Never use regular hosts style ala rsh/cp/..

Do a "man ssh" and search for "host keys"... or Google away.

Key management can be done via NIS maps or rdist/sync them around. I mean,
lots of discussion could go on here.

Cheers, -Ali

OpenPGP Key: 030E44E6
Was I helpful?:
War is evil, but it is often the lesser evil. -- George Orwell

Re: scp vs rcp - password question

Quoted text here. Click to load it

SSH keys in NIS maps? Do you have a URI? What are the map names
called? Is it for host keys, user keys, both?

A quick Google didn't turn anything up.

David Magda <dmagda at>, /
Because the innovator has for enemies all those who have done well under
the old conditions, and lukewarm defenders in those who may do well
under the new. -- Niccolo Machiavelli, _The Prince_, Chapter VI

Site Timeline