Hi,
They have to be provided with DNS servers for any internal or external sites, so that anyconnect user when he/she connects to vpn will get the DNS added to them..... if that is not possible..... host entry needs to added with the required URL's and IP address to the file.... so that lookup happens locally in his system itself.....
For DNS, you need to specify VPN settings with DNS server details.
For Host Entry Modification : C:\Windows\System32\drivers\etc\hosts --- open it using notepad and
10.0.0.1 cuckoonetworks.com add like this..... for eg...
Regards
Karthik