Express route circuit down

Question

Hi,

Our express route went down last week, and all I can see is this when I troubleshoot it. It is saying that the Host OS and Guest OS had maintenance, but not sure why our BGP peering session went down for like 6 hrs.

Answer 1

@JoelP

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I understand that you would like to troubleshoot your ExpressRoute downtime.

• You can use the AzureDiagnostics logs to understand what caused the BGP issue.
• Sample Kusto Queries : https://learn.microsoft.com/en-us/azure/expressroute/monitor-expressroute#sample-kusto-queries

You informed that the users experienced connectivity loss for almost 6 hours during this maintenance activity.

I suggested you can use the BGP Availability - Split by Peer metric to check if a BGP session was down or not.

However,

During maintenance between the Microsoft edge and core network, BGP availability will appear down even if the BGP session between the customer edge and Microsoft edge remains up.

So, if the users have not experienced any connectivity loss, I would say this should be an expected behavior.

Furthermore, you can check the past maintenance activities here : https://learn.microsoft.com/en-us/azure/expressroute/maintenance-alerts#view-past-maintenance

Thanks,

Kapil

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