Linux prohibits access to specified ip

How to disable access to specified ip in linux?

For example, it is brute force cracked by others, and others try to log in with different passwords:

 

So I want to directly disable access to these ips. What should I do?

Solution: Modify the configuration file /etc/hosts.deny

Put the IPs to be banned from ssh access in /etc/hosts.deny :

 

There is ip 117.136.38.47 in the config file.

Then when this ip tries to ssh login, it will:

 

The login is refused directly, and the user name and password will not be verified.

Contents of configuration file /etc/hosts.deny:

#
# hosts.deny    This file contains access rules which are used to
#               deny connections to network services that either use
#               the tcp_wrappers library or that have been
#               started through a tcp_wrappers-enabled xinetd.
#
#               The rules in this file can also be set up in
#               /etc/hosts.allow with a 'deny' option instead.
#
#               See 'man 5 hosts_options' and 'man 5 hosts_access'
#               for information on rule syntax.
#               See 'man tcpd' for information on tcp_wrappers
#
sshd:121.42.0.15
sshd:121.42.0.17
sshd:121.42.0.19
sshd:121.42.0.30
sshd:121.42.0.31
sshd:121.42.0.36
sshd:121.15.151.181

Use # to comment 

ip partial matching is also supported:

 

 

Reference: Solve the problem of Alibaba Cloud host being attacked 2:

http://hw1287789687.iteye.com/blog/2269701