The below IPs will need to be whitelisted on your primary nameserver allow-transfer access control list and firewall security policies to allow zone transfers.
Your zones will be on either PDNS, EDNS, SDNS or XTLD. If you are an SLD customer (not a registry), your zones are on PDNS. If you are a registry your zones are on either XTLD or PDNS platform. Contact Customer Support at https://www.ultraproducts.support if you are not sure which platform you are on.
PDNS Platform
Allow Transfer
23.21.200.163
23.21.206.251
50.112.240.144
50.112.240.145
54.75.253.83
176.34.183.208
52.201.103.62
52.87.134.132
34.205.12.198
52.201.155.234
52.201.155.120
52.39.68.132
35.165.213.102
52.10.123.90
52.10.63.3
Also Notify
54.217.202.161
107.21.214.87
54.245.253.13
23.21.48.87
23.21.59.232
XTLD Platform
Allow Transfer and Notify
156.154.161.94
156.154.162.94
156.154.163.94
116.51.28.217
156.154.35.142
2610:a1:3008:128::142
156.154.38.142
2610:a1:3014:128::142
156.154.39.142
2610:a1:3018:128::142
156.154.80.142
2610:a1:3038:128::142
156.154.76.142
2610:a1:3028:128::142
203.119.15.142
2610:a1:3070:128::142
156.154.181.142
2610:a1:3058:128::142
For additional notes, click here:
https://ultra-portalstatic.ultradns.com/static/docs/Zone_xfer_ips_new.html