sudo openconnect xx.xx.xxx.xxx:xxxxx
[sudo] password for xxxxxxx:
Attempting to connect to xx.xx.xxx.xxx:xxxxx
SSL negotiation with xx.xx.xxx.xxx
Server certificate verify failed: self signed certificate

Certificate from VPN server "xx.xx.xxx.xxx" failed verification.
Reason: self signed certificate
Enter 'yes' to accept, 'no' to abort; anything else to view: yes
Connected to HTTPS on xx.xx.xxx.xxx
GET https://xx.xx.xxx.xxx:xxxxx/
Got HTTP response: HTTP/1.1 303 See Other
GET https://xx.xx.xxx.xxx:xxxxx/webvpn.html
Error fetching HTTPS response