How to Enable Passwordless RSH Login in RHEL5
Posted: Thu May 02, 2013 4:29 pm
When you administer clusters, you will eventually encounter applications that still use rsh to connect between nodes.
In my place, we use Red Hat Enterprise Linux 5 (RHEL5) for the cluster nodes. In order for the application to run, we need to enable passwordless logins via rsh, in order for the Message Passing Interface & Node Management Software to work. There are a few ways to do this, this is how I did it. Security Professionals will be screaming though.
Firstly, make sure you have installed the rsh-server rpm package.
Make sure the rsh, rlogin, rexec, xinetd are turned on and then restart xinetd.
Edit your /etc/securetty file. Append the following
You’ll then need to create a .rhosts file in the user’s home directory, with the host names of the machines you wish to allow to connect. Note:These machines should be resolvable via either DNS or put in your /etc/hosts file.
Also, make sure the file permissions are 0600.
You should be able to rsh in now. 
In my place, we use Red Hat Enterprise Linux 5 (RHEL5) for the cluster nodes. In order for the application to run, we need to enable passwordless logins via rsh, in order for the Message Passing Interface & Node Management Software to work. There are a few ways to do this, this is how I did it. Security Professionals will be screaming though.
Firstly, make sure you have installed the rsh-server rpm package.
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[root@laxm1331 ~]# yum install rsh-server
Loaded plugins: product-id, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
5Server-x86_64 | 1.9 kB 00:00
5Server-x86_64/primary_db | 2.1 MB 00:00
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package rsh-server.x86_64 0:0.17-40.el5_7.1 set to be updated
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package Arch Version Repository Size
================================================================================
Installing:
rsh-server x86_64 0.17-40.el5_7.1 5Server-x86_64 40 k
Transaction Summary
================================================================================
Install 1 Package(s)
Upgrade 0 Package(s)
Total download size: 40 k
Is this ok [y/N]: y
Downloading Packages:
rsh-server-0.17-40.el5_7.1.x86_64.rpm | 40 kB 00:00
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : rsh-server 1/1
Installed:
rsh-server.x86_64 0:0.17-40.el5_7.1
Complete!
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[root@laxm1331 ~]# chkconfig rsh on
[root@laxm1331 ~]# chkconfig rexec on
[root@laxm1331 ~]# chkconfig rlogin on
[root@laxm1331 ~]# service xinetd restart
Stopping xinetd: [ OK ]
Starting xinetd: [ OK ]
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rsh
rexec
rlogin
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laxm1331 root
laxm1332 root
laxm1333 root
laxm1334 root
laxm1338 root
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chmod 0600 ~/.rhosts