What you should do is whitelist our router IP addresses in your firewall so that they won't get blocked. Our router clusters use many different IP addresses, so the best way to identify them would be by checking the hostname of the IP address. All of our router IP addresses use a similar hostname pattern which looks like this:
router-XXX.city.country.router.prioritynap.net
For example:
% host 199.201.109.25 25.109.201.199.in-addr.arpa domain name pointer router-1.ash.us.router.prioritynap.net.
