Airtel Network Issue Impacting Inbound Connectivity to India PoPs

The provider has confirmed that the affected path is now fully recovered. As a precaution, Airtel remains withdrawn from our eBGP peering for the India PoPs while we validate stability. We plan to reintroduce Airtel on July 1 with AS-path prepending applied, which will allow the path to carry traffic in a limited capacity while we continue to monitor performance.

We are marking this incident as resolved. The remaining actions, including reintroducing Airtel and later fully restoring it as a standard provider in our routing blend, are routine and should not introduce any further customer impact.

We completed the withdrawal of eBGP advertisements to Airtel in Bangalore, steering traffic onto healthy paths, and have continued monitoring since. Results have improved significantly, though some upstream paths through Airtel may still see impact in certain cases. Overall impact is reduced, and traffic will remain re-routed on Fortinet PoPs for the time being.

The provider has reported a fiber cut impacting this international connectivity and is working with local authorities on a resolution. No provider fix is available yet for the affected paths. The observed behavior is occurring outside our network, on provider-managed paths we do not control, and the impacted external cloud provider has not yet provided any update on routing around the issue. We will continue monitoring and share further updates as the situation develops.

An issue on Airtel's network is impacting inbound connectivity from many North American networks to our India PoPs. Both Fortinet-operated and cloud-hosted PoPs across India are affected.

SIA and SPA traffic to these PoPs may experience elevated latency and intermittent packet loss (upward of 30 to 40 percent). The issue is isolated to traffic traversing Airtel's network. Other paths into the region, as well as traffic within India, appear unaffected.

Mitigation in progress: We proactively withdrew our eBGP advertisements to Airtel in Pune to steer traffic onto healthy paths, and we are applying the same change in Bangalore. External cloud providers have also been notified so they can adjust routing on their side as needed. Note that the observed behavior is occurring well outside our network, on provider-managed paths we do not control.

If you have any questions regarding this incident, please contact FortiCare Support (https://www.fortinet.com/support/contact) and reference FortiSASE Operations ticket #528142.