BIND Update Issue

We have experienced a specific issue when we try to upgrade the bind version (from current to latest) in BIND DNS servers. As we noticed the location of the executable binaries ( named, dns-key etc) is changed (i.e /usr/sbin OR /usr/local/sbin) depending on the way you installed bind.
(i.e. From RPMs/ yum OR install from the source code)

You can check the location using following command
 which named 

The output will be somewhat like /usr/sbin/named or /usr/local/sbin/named as mentioned above.

When you try to upgrade bind with source code, by default the executable location will be /usr/local/sbin and you will ended up with server failure when restart the service.


The solution is as follows
First you need to download the source code and untar it to your home directory

wget -b source_code_url 

tar -xzvf bind-9.x.x.tar.gz

If your executable location is /usr/sbin you have to compile the source code with following parameters
./configure --sbindir=/usr/sbin

Then issue make and make install commands to install the new version

make

make install

Check whether it has upgraded using named -v command
named -v

Now restart the service ( server named restart OR /etc/init.d/named restart)

Note: If you have a doubt about what you will get after the upgrade... tar your executable folder and keep as a backup. You can have your old version once you untar the contents in the backed up and replaced it.

3 Steps to Perform SSH Login Without Password Using ssh-keygen & ssh-copy-id

Good Reference:
3 Steps to Perform SSH Login Without Password Using ssh-keygen & ssh-copy-id

Nice article which tells how you can configure ssh remote login without passwords.
I tried it with Ubuntu client and logged in to remote Fedora server without any issue.

Just one clarification: When you create the public and private keys using ssh-keygen command, if you enter a pass phrase it will be prompt at the login. So better to leave a blank when generating the keys.

Then copy the public key using following command as given in the link 

ssh-copy-id -i ~/.ssh/id_rsa.pub <remote_host_ip>


I had an issue when login to a Fedora server from another fedora host as I used a pass-phrase when generating the keys.

I found another issue with ssh-copy-id command, due to permissions/settings issue at the remote host, I was not able to use ssh-copy-id command to copy the public key.

I followed the below given steps and enable remote login with publickey authentication.

1. Copy the id_rsa.pub to the remote key using scp command
2. Login to the remote host with ssh
3. Make the .ssh folder in the home directory (If not available)
4. Append the id_rsa.pub to the .ssh/authorized_keys file (If authorized_keys file is not available, add the contents in the id_rsa.pub to it)

At the same time, check whether the sshd process is accepting the publickey authentication. ( Check the /etc/ssh/sshd_config file and enable it as follows)
"RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile      %h/.ssh/authorized_keys

Good reference on issues of ssh_copy_id
http://superuser.com/questions/189376/ssh-copy-id-does-not-work