From the course: Cisco Network Security: Secure Routing and Switching
Join today to access over 24,700 courses taught by industry experts.
Security implications of a native VLAN
From the course: Cisco Network Security: Secure Routing and Switching
Security implications of a native VLAN
- [Instructor] On a Cisco switch, the default configuration is to have a native VLAN out of the box. VLAN 1 is the only VLAN that exists, so this means that all ports are members of VLAN 1 by default. The native VLAN can be a security risk. It isn't tagged by default. If an access port is set to the same VLAN as the attackers, VLAN hopping is much more easily accomplished from the default VLAN. You can't delete VLAN 1, but you can assign all ports into different VLANs to make sure VLAN 1 isn't being used. Let's take a look. I'm in Packet Tracer, and I've already configured Switch One, and moved over the ports to VLAN 101. We'll do the same thing on Switch Two. Now, what you can see is that there's a VLAN mismatch, and that's because I haven't finished configuring Switch Two. First, we'll say show VLAN brief. And there you see VLAN 1 and all the ports that are assigned to VLAN 1. I added native VLAN 99, and we will…
Download courses and learn on the go
Watch courses on your mobile device without an internet connection. Download courses using your iOS or Android LinkedIn Learning app.
