Transit and Peering: How your requests reach GitHub

This post details the technical aspects of GitHub's network ingress and egress strategies, explaining the concepts of internet transit (billed by bandwidth, announced IP blocks via BGP) and peering (PNI and IXPs). It highlights the shift from relying solely on transit to incorporating peering, which now accounts for 60-70% of traffic, offering performance and availability benefits. The post also touches on GeoDNS for regional routing and the use of BGP route selection for traffic engineering, including incident response adjustments.