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, regardless of where you are logging in from 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, regardless of where you are logging in from 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).