CISCO Anyconnect plus MAC address filtering

[number9]

Hello,

I have been using openconnect for a while to connect to a CISCO 
Anyconnect server.
The server admins have decided to change their system to also include 
MAC based authentication,
where if they do not recognize a MAC address, one can not authenticate. 
I was told by their administrator
that "my vpn client" is not sending the MAC, or that it does not work. 
Has anyone heard of this?
I searched the mailing list archives and did not see any messages 
regarding this setup.

I do know one other user of this system that was using openconnect and 
he noted the same
issue, and had to switch to a different client. I am on Gentoo linux, 
and would like to continue
to use openconnect, if possible.

Any tips for troubleshooting, or has anyone heard of this issue? As a 
preemptive note, I have
zero insight into the server end (we are not allowed to touch it, see 
logs, etc).

Thanks.