Sentry is making changes to increase its reliability, which may require updates to firewall rules for uninterrupted service starting December 1st, 2020. The changes will affect inbound traffic to organization subdomains, which are used by Sentry's Data Source Names (DSNs). Customers with applications configured with DSNs that include organization subdomains will need to update their firewall rules to continue uninterrupted service. However, those without such configurations will not be impacted. The change aims to reduce latency for event ingestion from outside North America.