@mcreilly  My issue is identical to yours.  I have many 5508 and 3504 controllers that I can access via the web through our DMVPN network, however the ME 3802 I cannot do this. Like you I can ping and SSH to it, but when loading https it says transfe...

Did you find out why you couldn't access the web GUI from a different subnet?

Thank you for your reply. We also had to upgrade the end device firmware to support the new RFC 6842.

DId you find out if there is a way to disable the RFC 6842 requirement?  I have one piece of equipment that will not a DHCP address for this reason. Thank You.

Did you get this to work?  I have a very similar situation.