Hi,
I have setup 2 VLANs on my draytek router Vigor2860AC.
VLAN0 uses LAN1 10.0.99.0/24
VLAN1 uses LAN2 10.0.100.0/24

Both VLANS are setup to allow both SSIDS at both 2.4 and 5 ghz and all ports P1-P6 are all allowed.

under general setup i have allow all subnets to communicate in the InterLAN routing table.

However if i have a client with a LAN1 ip address, it cannot communicate with devices on LAN2 and clients on LAN2 are not able to use devices on LAN1.

Any help on what i am missing would be much appreciated.

Am i misunderstanding here. IT sounds like you are trying to assign two different subnets to a the same lan ports ? The Draytek help article here shows one subnet/vlan per port (so no lan 1 and lan 2 assigned to p1)

https://www.draytek.com/support/knowledge-base/4911

But you can assign multiple subnets/vlans to a port if you use vlan tagging. Here p2 connects to a switch where the vlan tags break out the subnets to the different switch ports as per how it's been configured.

https://www.draytek.com/support/knowledge-base/4912

I gues sthere is some confusion here, the Physical ports are a red herring as i am only really using wireless ports, so the configuration is on the SSID's rather than the port configurations.

so i have a vlan 1 on SSID 1 that asigns network 10.0.99.0 /24
Vlan 2 on SSID 2 assigns network 10.0.100.0 /24

if i have a device on SSID 1, it cannot be accessed by a device on SSID 2

hope this helps clear up the confusion and hopefully someone will clear up mine .

Perhaps if you explained your setup more fully, you might get more help.

Are one or both VLANs tagged? Are your devices VLAN tag aware (e.g., are they managed network switches)?
What kind of devices have you put on each VLAN?
What do you mean by devices on different VLAN'S can't "communicate"? What sort of communication are you hoping for?
Can devices on one VLAN ping devices on the other?
What are you trying to achieve?

I for one can't see why you would have two VLANs, both including all ports and all WiFi SSIDs, if you want all devices on one to talk to devices on the other?