Going through F5 setup with legacy catos switches and trying to setup LACP, I only couple of commands on forums and cisco docs:
CatOSSwitch (enable) set channelprotocol lacp 2 Mod 2 is set to LACP protocol. CatOSSwitch (enable) set port lacp-channel 1/1,2/1 Port(s) 1/1,2/1 are assigned to admin key 56
But, this is not enough, 1 more step is needed for this setup to work:
This one is quite obvious but there is a catch.
All the ports in port-channel need to have same native vlan. And here is the catch, since it is 801q VLAN trunk, you can’t use a 801q VLAN as native VLAN. So as soon as you set a native vlan not part of 801q tagging, you would be able to see all interfaces in lacp trunk in Big IP.