What are the most important security policies for LAN switching networks?

1 Device hardening

Device hardening is the process of configuring your network devices, such as switches, routers, and firewalls, to reduce their attack surface and prevent unauthorized access. This involves applying the principle of least privilege, which means granting only the minimum level of access and permissions required for each device and user. To protect your devices, you should change default passwords and usernames, disable unused ports and services, encrypt management and data traffic, apply access control lists (ACLs) and firewall rules, update firmware and software regularly, and enable logging and auditing.

2 VLAN segmentation

VLAN segmentation is the practice of dividing your LAN into smaller logical segments, called virtual LANs (VLANs), based on criteria such as function, location, or security level. This can help isolate and protect sensitive data and devices from other network segments, as well as reduce broadcast traffic and improve network performance. VLAN segmentation benefits include enhancing data confidentiality and integrity, restricting access to authorized users and devices, mitigating the impact of network attacks, and simplifying network management and troubleshooting.

3 MAC address filtering

MAC address filtering is the process of allowing or denying access to your network based on the media access control (MAC) address of each device. This address is a unique identifier assigned to each network interface card (NIC), enabling communication between devices on a LAN. By using MAC address filtering, you can prevent unauthorized devices from connecting or spoofing legitimate ones. Some of the methods include static MAC address filtering, which involves manually creating a list of allowed or denied MAC addresses on each switch port; dynamic MAC address filtering, which involves automatically learning and storing the MAC addresses of authorized devices; and port security, which limits the number of MAC addresses associated with each switch port. In doing so, you can ensure that your network is secure from any unapproved access.

5 ARP inspection

ARP inspection is the process of monitoring and validating the address resolution protocol (ARP) messages on your network. ARP is a protocol that maps IP addresses to MAC addresses, which are essential for data transmission on a LAN. ARP inspection can help you protect against ARP spoofing, which is a technique of sending forged ARP messages to trick devices into associating a malicious MAC address with a legitimate IP address. Its functions include comparing the ARP messages with the DHCP snooping database, checking the validity and consistency of the IP-MAC bindings, intercepting and discarding spoofed or malformed ARP messages, and preventing man-in-the-middle, denial of service, or data interception attacks.