Description of problem:
I have ocserv set to only give out ipv6 addresses. I can connect from the cli using openconnect just fine. trying to use NetworkManager fails wit, even when I have told the client to disable ipv4

Nov 07 16:24:10 ra.ausil.us NetworkManager[1206]: <info>  [1478557450.1750] audit: op="connection-activate" uuid="79eacf55-edb6-4f8b-a241-0ecf880885d1" name="ausil vpn" pid=2577 uid=217600001 result="success"
Nov 07 16:24:10 ra.ausil.us NetworkManager[1206]: <info>  [1478557450.1865] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: Started the VPN service, PID 4598
Nov 07 16:24:10 ra.ausil.us NetworkManager[1206]: <info>  [1478557450.2044] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: Saw the service appear; activating connection
Nov 07 16:24:16 ra.ausil.us NetworkManager[1206]: <info>  [1478557456.5394] keyfile: update /etc/NetworkManager/system-connections/ausil vpn (79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn")
Nov 07 16:24:16 ra.ausil.us NetworkManager[1206]: <info>  [1478557456.5671] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: VPN connection: (ConnectInteractive) reply received
Nov 07 16:24:16 ra.ausil.us NetworkManager[1206]: <info>  [1478557456.5998] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: VPN plugin: state changed: starting (3)
Nov 07 16:24:17 ra.ausil.us openconnect[4616]: Connected to 74.119.218.156:443
Nov 07 16:24:17 ra.ausil.us openconnect[4616]: SSL negotiation with 74.119.218.156
Nov 07 16:24:17 ra.ausil.us openconnect[4616]: Server certificate verify failed: signer not found
Nov 07 16:24:18 ra.ausil.us openconnect[4616]: Connected to HTTPS on 74.119.218.156
Nov 07 16:24:19 ra.ausil.us openconnect[4616]: Got CONNECT response: HTTP/1.1 200 CONNECTED
Nov 07 16:24:19 ra.ausil.us openconnect[4616]: CSTP connected. DPD 90, Keepalive 32400
Nov 07 16:24:19 ra.ausil.us openconnect[4616]: Connected as 2607:ff50:3:8:2c7a:32e1:27b7:5477/64, using SSL
Nov 07 16:24:19 ra.ausil.us openconnect[4616]: Established DTLS connection (using GnuTLS). Ciphersuite (DTLS1.2)-(RSA)-(AES-128-GCM).
Nov 07 16:24:23 ra.ausil.us openconnect[4616]: SIOCSIFMTU: Operation not permitted
Nov 07 16:24:23 ra.ausil.us NetworkManager[1206]: <warn>  [1478557463.8378] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: VPN plugin: failed: bad-ip-config (2)
Nov 07 16:24:23 ra.ausil.us NetworkManager[1206]: <warn>  [1478557463.8379] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: VPN plugin: failed: connect-failed (1)
Nov 07 16:24:23 ra.ausil.us NetworkManager[1206]: <info>  [1478557463.8382] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: VPN plugin: state changed: stopping (5)
Nov 07 16:24:23 ra.ausil.us NetworkManager[1206]: <info>  [1478557463.8383] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: VPN plugin: state changed: stopped (6)
Nov 07 16:24:23 ra.ausil.us NetworkManager[1206]: <info>  [1478557463.8394] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: VPN plugin: state change reason: unknown (0)
Nov 07 16:24:23 ra.ausil.us NetworkManager[1206]: <info>  [1478557463.8637] vpn-connection[0x564b6ac847d0,79eacf55-edb6-4f8b-a241-0ecf880885d1,"ausil vpn",0]: VPN service disappeared