License won't revalidate

So we have a customer whom activated their license by white listing https://wyday however they have a proxy in place and can't revalidate or deactivate the license now and we get can't connect to servers. Any info on this or ip addresses of the servers they are trying to contact so can get them into the exception list?

Nope, the wyday.com servers are behind DDoS protection. And we have multiple IP addresses that we change without notice.

Short answer: use the domain name. Modern routers & switches (anything of quality made in the last decade) allow whitelisting based on domain names.