2 Steps to restrict Jenkins access by IP address or Host Name

Steps to fresh jenkins installtion on on Apache Tomcat Server : http://www.automatethebox.com/2016/06/installing-jenkins-on-apache-tomcat.html

If Jenkins is installed on Tomcat Server 

1.  Add any of the below entry in the conf\context.xml file :
• <Valve className="org.apache.catalina.valves.RemoteAddrValve" allow="127.0.0.1"/><!--Allow from Ip Address-->
• <Valve className="org.apache.catalina.valves.RemoteAddrValve" deny="127.0.0.1"/><!--Deny from Ip Address-->
• <Valve className="org.apache.catalina.valves.RemoteHostValve" allow="yahoo.com"/><!--Allow from a Domain-->
• <Valve className="org.apache.catalina.valves.RemoteAddrValve" allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1|202.43.25.244"/><!--Allow from multipl ip's-->
2.  Restart the Tomcat Server

Now, when you try to access Jenkins url, you should get 403 error

If Jenkins is installed on Apache Server 

1. Add all of the below entries in the conf\.htaccess file to allow access from ip '45.67.87.67' and '10.66.62.0/24' LAN only
• Order Deny,Allow
• Deny from all
• Allow from 45.67.87.67
• Allow from 10.66.62.0/24
2. Restart the Apache Server

Now, when you try to access Jenkins url, you should get 403 error