About the number of BGP connections of ExpressRoute

@napblanket Here is a document that talks about the limits for Express Route- https://video2.skills-academy.com/en-us/azure/azure-resource-manager/management/azure-subscription-service-limits. Here, you can look under- ExpressRoute limits which explains all the details about the circuits and routes limitations for Express Routes.

Also note that, Each ExpressRoute circuit consists of two connections to two Microsoft Enterprise edge routers (MSEEs) at an ExpressRoute Location from the connectivity provider/your network edge. Microsoft requires dual BGP connection from the connectivity provider/your network edge – one to each MSEE. You may choose not to deploy redundant devices/Ethernet circuits at your end. However, connectivity providers use redundant devices to ensure that your connections are handed off to Microsoft in a redundant manner. A redundant Layer 3 connectivity configuration is a requirement for our SLA to be valid.

New ExpressRoute circuits can include two independent peerings: Private peering and Microsoft peering. Whereas existing ExpressRoute circuits may contain three peerings: Azure Public, Azure Private and Microsoft. Each peering is a pair of independent BGP sessions, each of them configured redundantly for high availability.

Hope this dissolves some of your doubts. If you have any more questions, please do let us know.
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