All Gearset requests, regardless of which instance you are using, originate from one of these static IP addresses:
52.30.99.114
34.246.69.148
34.246.80.170
52.208.77.76
If you are on the US instance of the Gearset app, you will also need access to these IP addresses:
44.238.181.240
54.203.218.9
44.233.15.112
If you are on the Australian instance of the Gearset app, you also need access to these IP addresses:
54.253.5.98
13.54.117.42
13.236.226.150
Depending on your corporate firewall settings, you may need to add logins from these IPs to the allowlist for Gearset to be able to connect to your on-premise version control system or to orgs with IP access restrictions enabled.
You should allow TCP port 443 for HTTPS (or TCP port 22 for SSH).