I need to create 3 vlans. This need arises from the fact that I have a Synology RT6600AX router with two MR2200AC mesh points attached. Unfortunately, the RT6600AX, when used in AP, the LAN ports are all trunks and belong to the main network, so you must necessarily use a managed switch that I have. On the flint, I created a VLAN device, then activating filter vlan, I created vlans 20, 30 and 40, assigning them to port 5 of the flint. Vlan20, 30 and 40 "U" while on the port I indicated "T" so that it transports (if I have understood correctly) the three vlans through that port to the switch. Then I created the bridge interfaces each with the name of each individual VLAN, for creating the subnets with DHCP. I chose port n.1 of the switch where to connect the bridge between flint and switch and here my enormous doubts begin! On the switch I was able to configure the three VLANs which I then also configured on the three ports where I connected the three synology. I was convinced that I had to configure the three VLANs as "U" but by doing so the VLANs did not receive IPs and consequently did not activate. When indicating "T" instead, the three wifi networks attached to the VLANs with IP assignment to the devices immediately began to work and everything works! What doesn't add up to me, however, is why do I have to set everything to TAGGED? I also understood that VLANs cannot communicate with each other unless you set firewall rules. So why is it that if I connect to one of the three wifis I can ping the other two? Any help would be a godsend and I thank you in advance.
VLAN20 VLAN30 VLAN40 Port5
"U" T
"U" T
"U" T





