Azure BGP ExpressRoute circuit failures

Question

Azure BGP ExpressRoute circuit failures

CJ Parker 0

Azure BGP ExpressRoute circuit is throwing 4xx errors throwing a message:

The platform has detected that at least 1 BGP session on at least one peering on your circuit is currently down and may be causing degraded performance. There is also an ongoing maintenance in progress on the secondary ExpressRoute router infrastructure.

We want to know if there is maintenance going on and is there any issues with the connectivity of our clients?

G Sree Vidya 825 Reputation points Microsoft External Staff

2025-04-16T06:07:28.2166667+00:00

Hello CJ Parker

Following up to see if the below suggestion was helpful. And, if you have any further query do let us know.
G Sree Vidya 825 Reputation points Microsoft External Staff

2025-04-17T05:56:04.45+00:00

Hello CJ Parker

I wanted to check if you had the opportunity to review the answer posted by useful in resolving your issue.

If it was helpful, please click "Upvote and Accept Answer" on his post to let us know.

We're here to help, so if you have any further questions, don't hesitate to ask.

Thank You.

1 answer

Your answer

G Sree Vidya 825 Reputation points Microsoft External Staff

2025-04-16T06:07:28.2166667+00:00

Hello CJ Parker

Following up to see if the below suggestion was helpful. And, if you have any further query do let us know.
G Sree Vidya 825 Reputation points Microsoft External Staff

2025-04-17T05:56:04.45+00:00

Hello CJ Parker

I wanted to check if you had the opportunity to review the answer posted by useful in resolving your issue.

If it was helpful, please click "Upvote and Accept Answer" on his post to let us know.

We're here to help, so if you have any further questions, don't hesitate to ask.

Thank You.

Answer 1

Hello CJ Parker

Yes, the message might indicate that Microsoft is performing maintenance on the secondary ExpressRoute router infrastructure.

Please validate the below details:

Verification: Check the Azure Service Health dashboard.

Go to Azure Portal > Service Health > Planned Maintenance or Service Issues.

Filter by ExpressRoute and your subscription/region to confirm ongoing maintenance.

Alternatively, review notifications in your Azure account under Notifications or check the Azure Status Page for ExpressRoute updates.

https://learn.microsoft.com/en-us/azure/expressroute/planned-maintenance

https://learn.microsoft.com/en-us/azure/expressroute/maintenance-alerts#view-past-maintenance

Since your BGP session is down we request you to check the below details:

Verify the BGP Sessions ensure that both primary and secondary BGP sessions are established. Dual BGP sessions are required for compliance with the SLA
Enable Diagnostics, in the Azure Portal, navigate to your ExpressRoute circuit and select Diagnose and solve problems. Run diagnostics to identify any performance issues.
Check AS Path Prepend Configuration: Ensure your on-premises devices are configured to accept the AS path prepend (AS 12076) used by Microsoft during maintenance. This ensures traffic can reroute to the redundant path without issues.
Sharing the similar thread for your reference. https://learn.microsoft.com/en-us/answers/questions/1376102/express-route-circuit-down

I hope this information helps! let me know if you have any further queries on this, we will be happy to assist you.

If it was helpful, please click "Upvote and Accept Answer" on his post to let us know.

We're here to help, so if you have any further questions, don't hesitate to ask.

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Azure BGP ExpressRoute circuit failures

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