Domain Name Resolution Failed. Here I am showing tunnel-command that you can try for specifying group-URL in it. The cause is not fully known but this is seen more frequently when people are using Google Public DNS DNS servers 8888 and 8844 Try using another DNS server such as your ISPs DNS server.
Select the Start button and then select the Control Panel. You cant establish a successful VPN connection using Cisco due to DNS issues. Tunnel-group your-tunnel webvpn-attributes group-url you URL enable.
AnyConnect failes to connect due to unsuccessful domain name resolution This community is for technical feature configuration and deployment questions.
Version 4 TCPIPv4 is double-click Internet Protocol. This could be caused by one of more of the following. Unsuccessful Domain Name Resolution is more of a client issue rather than VPN server. If the first solution did not work for you firewall restrictions could be preventing you from successfully performing DNS queries.