I have a big problem. I changed the deafult shell in /etc/passwd file for root. When I want to connect the the IP with telnet or ssh, it gives no shell error from the system. Is there any possibility for the creating a connecting to system with a different shell? may be with this log on operation with root user i can change etc/passwd file. Or any other idea... Anyone can help me on this?

just use a live cd - get knoppix or what ever. then you can use vi or something to edit the /etc/passwd file.....

I think the command to edit the passwd file is vipw, it's some special command to do it. Otherwise, I'm not sure it'll take the changes. You might consider looking into that.

is the issue that you can't log in or that you don't know how to edit /etc/passwd?

First of all, and you don't want to hear this now but, you should not log in remotely as root but as unprivileged user.
Furthermore shells are local to the system so there's no way I know you gonna succeed specifying one from remote. If you have any unprivved users in the wheel group, log in, su and use the -s arg and supplying any allowed shell from /etc/shells could do the trick.

Yes I can't log in. I take this error code after entering the root and password.

No shell
Connection closed by foreign host.

I don't know any other users password. I think the /etc/passwd file same as this one.

root:x:0:0:Super-User:/:/sbin/sh
daemon:x:1:1::/:/sbin/noshell
bin:x:2:2::/usr/bin:/sbin/noshell
sys:x:3:3::/:
adm:x:4:4:Admin:/var/adm:/sbin/noshell
lp:x:71:8:Line Printer Admin:/usr/spool/lp:/sbin/noshell
uucp:x:5:5:uucp Admin:/usr/lib/uucp:/sbin/noshell
smmsp:x:25:25:SendMail Message Submission Program:/:/sbin/noshell
nobody:x:60001:60001:Nobody:/:/sbin/noshell
noaccess:x:60002:60002:No Access User:/:/sbin/noshell
backup:x:510:1:Account for batch backup jobs:/backup:/bin/sh
pocuser:x:311:311::/opt/home/pocuser:/bin/ksh
db2udf1:x:202:202::/opt/home/db2udf1:/bin/ksh
mqm:x:301:301::/opt/mqm:/bin/sh
emcuser:x:7001:701:EMC Main User:/opt/home/pocuser/emc:/bin/ksh

well, the fact that you don't know another user name is a problem. as you could ssh as another user and do "su", which would allow you to edit /etc/passwd.

I guess a remote ssh command wouldn't work either. But you might try it:

ssh <remote host> chsh -s <path to shell> root

if that makes sense.....

is it a host you cannot get to physically?

I try the command it doesn't make any sense...
I take this error code:

root@<hostip>'s password:
Permission denied, please try again.

The root password can not be used here. I can't log in.
Is there any possibility for copying same etc/passwd file to this ip.

And I have same users in other system exacly doing the same operation for this system. Is there any possibility for finding any users password in this system?

This isn't some covert attempt to crack/comprimise this system is it?

You won't answer my question about whether you have physical access.......

I'm very sorry. I didn't see the question because of my confusion.

No I don't have any physical access.

I find a physical access for the system. I hope this should solve my problem. I'm going crazy