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Are there any potential problems with VLANs?
Attacks on VLANs are easier to perpetrate than you might think. And typically, there are several known applications (including yersinia, dsniff and macof) that provide potential attackers with the tools to penetrate VLANs and cause chaos. VLANs are implemented at layer 2 of the OSI network model.
How can you secure the VLANs in the switch?
First, avoid putting any hosts on the default VLAN (VLAN 1). Second, be sure that the native VLAN on every trunk port is an unused VLAN ID. Finally, enable explicit tagging of the native VLAN for all trunk ports. Check out the rest of our blog to learn about other considerations for a Virtual Local Area Network.
What are the security benefits of VLANs?
Improved security: Using VLANs improves security by reducing both internal and external threats. Internally, separating users improves security and privacy by ensuring that users can only access the networks that apply to their responsibilities. External threats are also minimized.
How are VLANs and security affect your network?
VLANs and Security ¶ 1 Segregating Trust Zones ¶. Because of the possibility of misconfiguration, networks of considerably different trust levels should be on separate physical switches. 2 Using the default VLAN1 ¶. 3 Using a trunk port’s default VLAN ¶. 4 Limiting access to trunk ports ¶. 5 Other Issues with Switches ¶.
Is it possible to misconfigure a VLAN in a switch?
VLANs are not inherently insecure, but misconfiguration can leave a network vulnerable. There have also been past security problems in switch vendor implementations of VLANs. Because of the possibility of misconfiguration, networks of considerably different trust levels should be on separate physical switches.
How to mitigate an attack on a VLAN?
Manually configure access ports and disable DTP on all access ports. Manually configure all trunk ports and disable DTP on all trunk ports. Shutdown all interfaces that are not currently in use. To prevent a Double Tagging attack, keep the native VLAN of all trunk ports different from user VLANs. Switches were not built for security.
How does double tagging attack on VLANs work?
Double tagging occurs when an attacker adds and modifies tags on an Ethernet frame to allow the sending of packets through any VLAN. This attack takes advantage of how many switches process tags. Most switches will only remove the outer tag and forward the frame to all native VLAN ports.