using hosts.allow and hosts.deny to control sshd connection in ubuntu
please make sure your hosts.allow works first, or you will lost control after create hosts.deny.
adding your ip range which allow using sshd for example 192.168.0.1/24 :
vi /etc/hosts.allow
sshd: 192.168.0.1/24
deny all other ip using sshd :
vi /etc/hosts.deny
sshd:all
deny all other ip excpet ip range :
vi /etc/hosts.deny
ALL:ALL EXCEPT 192.168.0.1/24
Other useful command :
find program full path by ps -auxwe
ps -auxwe |grep "target pid or port"
find all connection to your machine currently
netstat -tunpla
netstat -tunplac <<< monitoring continuously by adding -c
reference link :
https://www.centos.org/docs/rhel-rg-en-3/s1-tcpwrappers-access.html
PREVIOUSwhat is my ip address for linux
NEXTfallocate