If you have error warning on CSF (ConfigServer Security & Firewall) on Linux servers when start or restart CSF like the following message:
*WARNING* Binary location for [HOST] [/usr/bin/host] in /etc/csf/csf.conf is either incorrect, is not installed or is not executable
It’s caused by bind-utils package not installed.
To resolve this problems, for Centos 6/7 and RHEL 6/7 simply run this command to install bind-utils:
# yum install bind-utils -y
To resolve this problems, for Ubuntu or Debian simply run this command to install bind-utils:
# apt-get install dnsutils -y
Then restart CSF with command:
# csf -r