Need to construct a tmsh command

I believe, at a minimum, you need to add the HTTP profile in the create statement to keep the virtual from defaulting to a fastL4. Here's what I've tested:

create ltm virtual testvip1 { destination 10.10.10.11:80 profiles add { http } }
modify ltm virtual testvip1 pool local-pool
modify ltm virtual testvip1 source-address-translation { type automap }
modify ltm virtual testvip1 profiles add { oneconnect }
modify ltm virtual testvip1 vlans add { external } vlans-enabled

You also don't need to add the tcp profile and address and port translation because they're enabled by default on a standard virtual server.