topic Re: Troubles with RSH from Linux in Operating System - HP-UX

Troubles with RSH from Linux

Kevin McKee — Wed, 05 Jan 2005 10:09:44 GMT

I'm having some troubles remote shelling from Linux Red Hat Enterprise ES 3 to HP-UX 10.20. I AM able to type rsh hostname from my Linux box and successfully connect to the HP-UX box. However, if I issue a command along with the RSH like rsh hostname touch /tmp/test.log, I simply get no response. In the SYSLOG I see the following entries:

When doing rsh hostname and successfully connecting:
usage: rlogind [-l] [-n]
Connection from x.x.x.x on illegal port

When doing rsh hostname touch /tmp/test.log and receiving no output:
usage: remshd [-ln]

Any input would be greatly appreciated.

Thanks in advance,
Kevin

Re: Troubles with RSH from Linux

Stephen Keane — Wed, 05 Jan 2005 10:22:06 GMT

Use remsh on HPUX not rsh.

Re: Troubles with RSH from Linux

Patrick Wallek — Wed, 05 Jan 2005 10:31:21 GMT

When doing multiple rsh commands, they should be enclosed in quotes and separated by a semicolon (;).

Try this and see what happens:

From RH Linux:

# rsh hostname "touch /tmp/test.log ; ls -l /tmp/test.log"

I think rsh may be getting confused with the argument to touch.

Re: Troubles with RSH from Linux

Kevin McKee — Wed, 05 Jan 2005 10:37:58 GMT

Thanks for the input, but unfortunately that doesn't work. I still get the same response in the SYSLOG on the HP side.

Re: Troubles with RSH from Linux

Ermin Borovac — Wed, 05 Jan 2005 22:47:08 GMT

Do you have firewall (iptables) enabled on the linux box?

Remote shell server (remshd on hp-ux) will try to open inbound connection to your linux box in order to pass stderr. This connection is made on a random port below 1023.

Please note that 'rsh ' is handled by rlogind and 'rsh ' by remshd. This explains why 'rsh ' works (rlogind doesn't make any inbound connections).

Re: Troubles with RSH from Linux

Kevin McKee — Thu, 06 Jan 2005 08:25:57 GMT

I wondered if it was something to do with trying to connect back to the Linux box as you said, but unfortunately I'm not familiar with that side of things. Can you tell me how to check if those ports are open or not? We're on an internal network so I have no trouble opening those ports if required.

Thanks

Re: Troubles with RSH from Linux

Stephen Keane — Thu, 06 Jan 2005 08:40:58 GMT

Do you have kerberos running on the Linux box?

Re: Troubles with RSH from Linux

Kevin McKee — Thu, 06 Jan 2005 10:26:14 GMT

How do I tell if I'm running Kerberos or not?

Re: Troubles with RSH from Linux

John Poff — Thu, 06 Jan 2005 11:01:11 GMT

Hi,

Do a 'rpm -qa | grep krb' to see if you have the Kerberos packages installed. Do a 'chkconfig --list kshell' to see if you have the Kerberos rsh commands enabled.

JP

Re: Troubles with RSH from Linux

Kevin McKee — Thu, 06 Jan 2005 12:11:52 GMT

This is what comes up for the rpm -qa
krbafs-utils-1.1.1-11
krb5-libs-1.2.7-19
krbafs-1.1.1-11
krb5-workstation-1.2.7-19
pam_krb5-1.70-1
krbafs-devel-1.1.1-11
krb5-devel-1.2.7-19

and it says that KSHELL is OFF

Re: Troubles with RSH from Linux

Ermin Borovac — Thu, 06 Jan 2005 19:57:37 GMT

You can check if firewall is active on the linux side with

# iptables -L

You can temporarily disable it to see if it helps with rsh problem

# service iptables stop

If you want to keep the firewall running, but enable rsh, insert the following rule to /etc/sysconfig/iptables before first line with '-j REJECT' action.

-A RH-Firewall-1-INPUT -p tcp -s --syn --dport 1001:1024 -j ACCEPT

Then re-enable firewall with

# service iptables start

Also make sure that on linux system you are executing /usr/bin/rsh, NOT kerberos rsh (/usr/kerberos/bin/rsh).

Re: Troubles with RSH from Linux

Kevin McKee — Fri, 07 Jan 2005 08:42:04 GMT

Fantastic. I didn't realize there were to RSH's, so simply by specifying /usr/bin/rsh - that worked!

Thank you so much