The VLAN packet
Before trying to understand VXLAN, let's go back to the fundamentals of a VLAN packet. How does tagging work in a VLAN packet? It's very simple concept: 4 bytes are inserted into the Ethernet header field (IEEE), which are a combination of a 2-byte Tag Protocol Identifier (TPID) and 2 bytes of Tag Control Information (TCI). The priority field is a 3-bit field that allows information priority to be encoded in the overall frame, 0 being the lowest priority and 8 the highest value. CFI is typically a bit used for compatibility between Ethernet and token ring networks and if the value is 0, those are Ethernet switches. Last but not the least, we have the VLAN field - VID:
The act of creating a VLAN on a switch involves defining a set of switch ports, and end devices get connected to these ports. They all become part of that VLAN domain which eventually stops a broadcast not to be forwarded to another set of VLANs. I know whatever we have discussed so far...
