Re: help --> rlogin

["Binand Raj S." <binand@xxxxxxxxxxxxxxxxxxxxx>]

sudheer@xxxxxxxxxxxxx forced the electrons to say:
> 
>   Hi ,
>  
>  i couldn't solve the problem. whatever combinations i tried ,they all
> are giving the same error
>  
> " 10.x.x.x:  Address already in use"
> 
> but from my machine to all other machines in the network, i'm able to
> login using rlogin.
> 
> sudheer

My $ 0.02 on this...

The error means that the port which the rlogin program is trying to open is
already opened by another program. The rlogin/rsh/rcp programs open a port in
the range 512-1023, and then try to connect to the remote server. Since ports
from 1-1024 are reserved for the superuser, the server at the remote end can
check the client's port number and decide if it is a valid client, or someone
trying to break in. This step is a primitive security measure, since these
programs allow users to login without giving their passwords.

Each invocation of the rlogin program needs two ports, so it forks. This
is the reason that you see two rlogins in your ps listing when you have
rlogin'ed to another system.

A possible reason for this error is that too many rlogin/rsh/rcp
invocations are running on the client machine. If you have many sockets
applications running, there will not be many ports available in the
512-1023 range. Since there are 512 ports in this range, at max only 256
combined invocations of rlogin/rsh/rcp can coexist on a system. Check yours
and other users' cron/at schedules to see if someone is hogging these reserved
ports.

Also, even though I don't think so, see if the setuid bit is set on your
rlogin client program. If this were the case, the error message should have
been different.

A third reason could be that your rlogin program itself is buggy. You can try
reinstalling it (very improbable).

You might have wrongly compiled your kernel, with the upper limit on the
reserved ports reduced from its default value of 1024. Recompile the kernel.

Anyway, as I said, the security authentication of rlogin/rsh/rcp is quite
primitive, so consider downloading and installing the ssh package (secure
shell)?

Regards,

Binand

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