Does all traffic in a VLAN aware switch goto the router?

Question

Background: Router (ER-X) connected to a VLAN aware Switch In the router, I have setup my VLANs and rules for allowing traffic between VLANs.

Question: The switch is setup with PVIDs. If I have traffic between two devices on the switch in the same VLAN, does that traffic stay in the SWITCH or does it need to go up to the router?

The real reason is that my ER-X has wireguard installed. When hw offload is enabled, wireguard is extremely slow (maybe this is a bug), but I can get gigabit speeds in my network. When hw offload is disabled, wireguard works normally, but I only get about 1/3 gigabit speeds in my network. I'm wondering if installing a VLAN aware switch as described above will allow me to gigabit speeds on my network while keeping hw offload disabled on my ER-X.

Answer 1

A VLAN aware switch is a switch that can tag its ports as belonging to a particular VLAN. A port can be configured to be in any given VLAN or none at all.

When a port receives a broadcast frame incoming, it will only send that broadcast out on ports that are in the same VLAN(s) as the receiving port. The VLAN represents a barrier at the Layer 3 level (Network).

Thus if the two devices are in the same VLAN, the traffic does not (usually) need to pass through the router, depending on the network segments.

If you look at the following diagram:

Here, nodes on the 192.168.1.0 network must go to the router when trying to communicate with nodes on the 192.168.2.0 network, even though all of the computers are connected to the same switch.