I have a connection coming into the house, then into a Synology router. I have 2 VLANS set up, the default one and a 2nd one called Secure. I don't have Ethernet run in my house but we have 6 coax ...

Unless there's no other option, you should ditch USB-Ethernet adapters ...

I'm interested in finding out out vlan tagging in respect to isa server. We help from you guys I was able to get it working with a clients sonicwall but I would like to know how tags could be ...