Block Telnet via ACL

 

Topic: - Block Telnet via ACL on Cisco Packet Tracer​

My task is that how to block telnet for specific network and allow for specific network using ACL configuration. In this task I am going to block the network of Manufacturing to access telnet of Router-1 via telnet, but the department of IT & Server can access Router-1 via telnet.

Everyone must use this link for Practical of ACL:)

https://1drv.ms/u/s!ArXqNRuYO5xNmC7LfCdC1317qDHm?e=ZNX8ba

Step-1) Draw network topology diagram and using any routing. In my case I used RIP routing.

Step-2) Configure Telnet on Router-1

R-1(config)#line vty 0 1

R-1(config-line)#password telnet

R-1(config-line)#login

R-1(config-line)#exit

R-1(config)#

Step-3) Configure ACL on ROuter-1 to block the network of Manufacturing Department (192.168.10.0/24) and allow the department of IT(192.168.12.0/24) & Server(192.168.13.0/24).

R-1(config)#access-list 2 permit 192.168.13.0 0.0.0.255

R-1(config)#access-list 2 permit 192.168.12.0 0.0.0.255

R-1(config)#access-list 2 deny 192.168.10.0 0.0.0.255

R-1(config)#line vty 0 1

R-1(config-line)#access-class 2 in

Step-4) You can see PC from network of IT_Deparment(192.168.12.0/24) can telnet on Router-1 because it's allowed in ACL.

C:\>telnet 192.168.11.1

Trying 192.168.11.1 ...Open

User Access Verification

Password:

R-1>

Step-5) Now you can also see PC from network of Manufacturing_Department(192.168.10.0/24) are not able to do telnet on Router-1 because this network has been blocked from doing telnet Router-1.

C:\>telnet 192.168.11.1

Trying 192.168.11.1 ...Open

[Connection to 192.168.11.1 closed by foreign host]

C:\>