The target machine would receive and process the frame, and that would make the VLAN Hopping Attack successful. Let’s take an example assuming an attacker is connected to switch A to a port in VLAN1, which is also the native VLAN on the trunk connection between switch A and switch B. The target machine is connected to a port to switch B in ...
IEEE 802.1Q – VLAN Tagging and Trunking in Networking IEEE 802.1Q is the networking standard that defines VLAN (Virtual Local Area Network) tagging on Ethernet frames. VLANs allow network administrators to segment a physical network into multiple logical networks, improving security, efficiency, and management.
In this discussion, lets explore the best ways to set up Inter-VLAN Routing on Cisco devices, using simple explanations and clear examples to help configure network efficiently.
The native vlan is most useful when going to study voip. As one port on the switch will connect to the IP phone, and a PC will connect to the phone. So we end up having two devices attached to the same port. What ends up happening is a vlan is made for the phones, which is prioritised, and the data traffic (from the PC) is left untagged. This is one commonly known way of using the native vlan.
In general VLAN is a concept of segregating a physical network, so that separate broadcast domains can be created. Private VLANs (PVANs) will split the primary VLAN domain [also a segregated network] into multiple isolated broadcast sub-domains. It’s like the nesting concept – creating VLANs inside a VLAN.
In reality a VLAN tag is inserted in the Ethernet frame like this: The 802.1Q (dot1q, VLAN) tag contains a VLAN-ID and other things explained in the 802.1Q Standard. The first 16 bits contain the "Tag Protocol Identifier" (TPID) which is 8100. This also doubles as the EtherType 0x8100 for devices that don't understand VLANs.
Remove IP addressing from Java-SW and Rava-SW VLAN interfaces. Configure trunk ports between the access switches and Core. DO NOT FILTER VLANS. Inter-VLAN routing should be done exclusively by the Core switch. Disclaimer: these tips don't ensure a good design, only are suited to fix the problem with routing between the VLANs in this example 😊
To solve VLAN limitations in data centers and cloud, so it can provide scalability by allowing Layer2 encapsulated in UDP or so it extends VLAN. This is called MAC-in-UDP (UDP port 4789) encapsulation.
The switch takes the received frame and associates it to that VLAN internally while processing. dot1q tags are only inserted into the frame header if it is sent out a trunk port on any non-native VLAN. You can test this by connecting two switches together on access ports, and assign two different VLANs to the ports. Traffic will pass just fine.
What is the native vlan? what is the point of the native vlan? i understand traffic in the vlan is untagged, but the tags are removed before they are sent out the access port, so why have traffic over the trunk links. ISL works without a "native vlan" why does 802.1q use it?
