ALC experiment

1. Overview of ALC

Definition of ALC: Access Control List (ACL) is a list of instructions for router and switch interfaces to control the data packets entering and leaving the port.

2. ALC application

There are two applications of ACL:
1. ACL applied on the interface-----filtering data packets (original destination ip address, original destination mac, port quintuple)
  2. Applied in routing protocols-------Match the corresponding routing entry
3. NAT, IPSEC VPN, QOS-----match the data flow of interest (match the data flow I set)

3. The working principle of ALC

When the data packet passes through the interface, since the interface has enabled acl, the router will check the packet and then deal with it accordingly.

4. Types of ALC

• No. 2000-2999---Basic ACL---Match data according to the source IP address in the data packet (which IP address the data came from)
• Number 3000-3999---Advanced ACL----Match data according to the source, destination IP, source, destination port, and protocol number in the data packet
• Number 4000-4999---Layer 2 ACL, MAC, VLAN-id, 802.1q

5. Experiment

The first step: set the IP address of client 1, 2 server 1, 2

Step 2: Configure the router

Step 3: Do not allow 192.168.1.1 to access 192.168.2.1

Step 4: Test