I have a home user who has had to replace his router. He installed a Vigor 2820vn, since then he cannot connect to our Citrix farm. We configured a new Vigor 2820n and sent that to him to use, but he is getting the same problem still. Both routers have the latest firmware at the time of this post.
On the Sonicwall firewall we are getting error messages as follows
Probable TCP NULL scan dropped and Fragmented packet dropped.