DYNDNS + MULTIWAN ????
I have 6 wans being load balanced and I need to have dyndns addresses for RDP (remote desktop) logins.
not sure, what you want to accomplish.
Do you want one public hostname for the complete trunk of your WANs?
The only way I can think of to achieve that is to install pfSense on a hosted webserver with a big uplink as a "RDP gateway".
Then configure VPNs on each WAN link of your local pfS box to that server.
Load Balance the VPNs.
Then connect your RDP clients to the webserver.
That means a lot of configuration and security thoughts and some $ for the hosted server and bandwidth.
What you can do without additional costs is to build gateway groups (e.g. 2 gateways per group for redundancy) and assign the DynDNS name to a group.
But AFAIK in that scenario only one gateway is used, so that's not loadbalancing.
You could only do some manual "loadbalancing" setting your clients up to use different DynDNS hosts and therefore gateway groups.
Hope this could lead you to further steps.