Free CCNA 200-301 Course 28-06: Numbered ACLs Lab Demo

Summary

In this informative lecture, the presenter guides viewers through configuring Access Control Lists (ACLs) for network security using a CCNA course lab demo in GNS3. The session covers setting up a standard numbered ACL to block traffic from a specific subnet while allowing it from another, and an extended numbered ACL to permit telnet access from a single host. The practical demonstration includes applying the ACLs to the correct interfaces and testing their functionality to ensure the desired traffic is allowed or denied, effectively securing the network according to the given scenarios.

Takeaways

• 📚 The lesson focuses on configuring Access Control Lists (ACLs) in a CCNA course, with lab exercises available for download.
• 🔗 The link to download the hands-on lab exercises is provided in the description of the lecture.
• 📌 The lab demo involves routers R1 and R2, with PCs in the 10.0.1 subnet and PC3 in the 10.0.2.0/24 subnet.
• 🛠️ Routing has been pre-configured for successful ping tests between the devices, confirming network connectivity.
• 🚫 The security task is to prevent PCs in the 10.0.2 network from accessing R2 at 10.0.0.2, while allowing PCs in the 10.0.1 subnet to maintain connectivity.
• 🌐 Standard ACLs can only filter based on source IP address, while Extended ACLs can specify both source and destination addresses.
• 🔄 The standard ACL is applied to the external FastEthernet 0/0 interface on R2 to block traffic from the 10.0.2 subnet.
• 🔒 The ACL configuration includes a deny statement for the 10.0.2.0/24 subnet and a permit statement for the 10.0.1.0/24 subnet.
• 📈 The ACL is tested by pinging from PCs in the 10.0.1 subnet to R2 and ensuring that PC3 from the 10.0.2 subnet cannot reach R2.
• 🔐 The second scenario involves configuring a numbered extended ACL to allow telnet access from PC1 to R2, while denying it from other PCs.
• 🔍 The extended ACL permits TCP traffic from host 10.0.1.10 (PC1) to R2 on port 23 (telnet) and denies the same for the 10.0.1.0/24 subnet.
• 🎯 The extended ACL is applied inbound on the FastEthernet 0/0 interface of R1 to secure the telnet access as close to the source as possible.

Q & A

What is the main topic of the lecture?

The main topic of the lecture is configuring access control lists (ACLs) with a lab demo as part of a complete CCNA course.

How can you access the hands-on lab exercises?

You can access the hands-on lab exercises by downloading them from the link provided in the description of the lecture.

What are the two routers and the three PCs named in the lab scenario?

In the lab scenario, the two routers are named r1 and r2, and the PCs are named pc1, pc2, and pc3.

What is the IP subnet for pc1 and pc2?

Pc1 and pc2 are in the 10.0.1 subnet.

Which subnet does pc3 belong to?

Pc3 is in the 10.0.2.0/24 subnet.

What is the first security task given to the network administrator in the scenario?

The first security task is to configure the network so that PCs in the 10.0.2 network have no connectivity to r2 at 10.0.0.2, while PCs in the 10.0.1 subnet maintain connectivity to r2.

What type of ACL is used to block traffic from the 10.0.2 subnet to r2 while allowing traffic from the 10.0.1 subnet?

A standard numbered ACL is used to block traffic from the 10.0.2 subnet to r2 while allowing traffic from the 10.0.1 subnet.

Where is the standard numbered ACL applied in the router to achieve the security task?

The standard numbered ACL is applied outbound on the FastEthernet 0/0 interface of r2.

What is the second scenario's security task in the lecture?

The second scenario's security task is to permit telnet access from pc1 to r2, allowing only the administrator workstation to access the router remotely, while denying telnet access from any other PC or subnet.

What type of ACL is used for the second security task, and what are its characteristics?

An extended numbered ACL is used for the second security task. It allows specifying both source and destination addresses and the protocol (in this case, TCP for telnet).

How is the extended numbered ACL applied in the router for the second scenario?

The extended numbered ACL is applied inbound on the FastEthernet 1/0 interface of r1, which is the interface connected to the PCs.

What is the result of applying the ACLs in the lab scenario?

After applying the ACLs, pc1 maintains connectivity to r2 and can telnet to it, pc2 is unable to telnet to r2 as expected, and pc3 remains unable to reach r2 due to the previously applied standard ACL.