Blocking IP Addresses on Your Dell Force10 S4810P During a DDoS Attack

What You’ll Need:

• A Dell Force10 S4810P switch
• A console cable or network access to the switch
• Terminal application (like PuTTY for Windows or Terminal for macOS) or SSH client

Steps:

1. Connect to your Dell Force10 S4810P switch: Use a console cable or SSH to connect to your switch. (Refer to the previous tutorials for detailed instructions on how to do this.)
2. Enter the configuration mode: At the command line prompt, type configure and press Enter.
3. Define an Access Control List (ACL) for the IP addresses you want to block: ACLs are used to control network traffic based on various criteria, including IP addresses. Use the ip access-list extended <ACL-name> command to create a new ACL. Replace <ACL-name> with a name for your ACL. Example: ip access-list extended BLOCK_DDOS
4. Add entries to your ACL to block the IP addresses: Use the deny ip host <IP-address> any command to add entries to your ACL that block specific IP addresses. Replace <IP-address> with the IP address you want to block. Example: deny ip host 192.0.2.1 any You can repeat this step to block multiple IP addresses.
5. Apply the ACL to an interface: Identify the interface(s) you want to apply the ACL to. For example, to choose Ten Gigabit Ethernet port 0/1, you would use the command interface TenGigabitEthernet 0/1 and press Enter. Then, apply the ACL to the interface using the ip access-group <ACL-name> in command. Example: ip access-group BLOCK_DDOS in
6. Save your configuration: Once everything is set up to your satisfaction, use the end command to exit configuration mode, then copy running-config startup-config to save your changes. If you don’t do this, your configuration will be lost when the switch is rebooted.

Blocking IP addresses at the switch level is a potent tool during a DDoS attack. It allows you to prevent traffic from the attacking IPs from entering your network, thus mitigating the impact of the attack.