See the attached photos for what I have setup.
VLANs Tab.jpg
VLAN Tab.jpg
Port 1 is the trunk port and 2-5 are members of the various VLANs. Native VLAN is 10. SFP port is not used. The other end of the trunk is setup correctly, I tested it by replacing the RB with a Cisco 3560.
Let me make sure I get what your trying to do....
You want port 1 to serve as a trunk for VLANs 1, 10, 20, and 30. You want port 2 to serve as an access port for vlan 20, 3 as an access port for 30, and 4 as an access port for 10. Is that correct?
If so what I think you want to do is set the mode for ports 2-4 to strict, only accept untagged, set the egress to strip always, set the default for port 2 to 20, 3 to 30, and 4 to 10. In the VLANs tab I think you want to set the appropriate VLANs on the access ports (2 to 4) to always strip.
I "think".... their documentation on this is pretty sparse.