Hello @Bharaniraj Iyyamperumal ,
Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.
An ExpressRoute circuit is created on a physical connection between Microsoft and an ExpressRoute Partner. The physical connection has a fixed capacity. To upgrade a circuit, the physical connection should allow additional capacity. If the physical connection for your existing circuit doesn’t have capacity for the upgrade, then you need to create a new circuit to be able to change the circuit size. You can follow the below article with the recommended migration steps which minimize down time and disruption to your production workload.
Refer: https://learn.microsoft.com/en-us/azure/expressroute/circuit-migration
But looking at your statement "New links were provisioned by the service provider", I believe the capacity for the physical connection was increased. Please confirm this.
If your existing physical connection allows for a 10Gbps upgrade, you can go ahead and upgrade the circuit bandwidth directly from the portal and make any necessary changes to the circuit & peerings. Post which you can link your Azure Vnet to the ExpressRoute circuit for connectivity as needed.
Refer: https://learn.microsoft.com/en-us/azure/expressroute/about-upgrade-circuit-bandwidth
Kindly let us know if the above helps or you need further assistance on this issue.
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