Here is the list of IPs that you can whitelist against the firewall.
192.174.80.197
192.174.90.236
156.70.5.9
156.70.2.4
192.174.90.234
192.174.93.180
192.174.90.233
192.174.86.56
147.253.210.51
147.253.216.16
156.70.23.184
156.70.23.185
156.70.5.12
192.174.85.36
156.70.23.182
156.70.23.183
192.174.80.250
192.174.80.241
192.174.85.35
192.174.90.235
167.89.89.21
168.245.48.99
167.89.94.204
149.72.189.233
149.72.174.183
149.72.211.56
149.72.188.78
167.89.85.85
167.89.126.37
149.72.168.84
54.240.38.192
54.240.38.193
54.240.38.194
54.240.38.195