How to setup azure route server in existing Vnet where Gateway subnet is already there?

Question

How to setup azure route server in existing Vnet where Gateway subnet is already there?

Anonymous

I am setting up new Route server in Vnet where Gateway subnet is already exist.As per MS steps, I am going to do peering among NVA and Route server. What to do with Gateway subnet when we deploy Azure route server.
Do we require to peer Gateway subnet with Route server OR Under route server configuration, enable " AllowBranchToBranchTraffic" only

KapilAnanth 49,876 Reputation points Moderator

2024-09-10T10:13:15.69+00:00

@Kiran Krishnaji Patil ,

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

I see akinbade abiola has addressed your queries. Just enabling branch-to-branch would exchange routes between the gateway and the Route Server.Please let us know if we can be of any further assistance here.

Thanks,

Kapil

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KapilAnanth 49,876 Reputation points Moderator

2024-09-10T10:13:15.69+00:00

@Kiran Krishnaji Patil ,

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

I see akinbade abiola has addressed your queries. Just enabling branch-to-branch would exchange routes between the gateway and the Route Server.Please let us know if we can be of any further assistance here.

Thanks,

Kapil

Please Accept an answer if correct.

Original posters help the community find answers faster by identifying the correct answer.

Answer 1

Abiola Akinbade 30,500 Volunteer Moderator

Hello Kiran Krishnaji Patil,

Thanks for your question

There is no need to peer the Gateway subnet with the Route Server. The AllowBranchToBranchTraffic setting under the Route Server configuration and appropriate BGP peering should suffice for handling the routing within the VNet. You'll need to configure BGP peering between the NVA and the Route Server.

See: https://learn.microsoft.com/en-us/azure/route-server/peer-route-server-with-virtual-appliance?source=recommendations

You can mark it 'Accept Answer' and 'Upvote' if this helped you

Regards,

Abiola

Anonymous

2024-09-12T05:57:29.94+00:00

I have one more question that, I am placing route server in VNET which is having Gateway subnet. Is there any impact on Gateway subnet service OR any downtime required ?

See Warning Section
KapilAnanth 49,876 Reputation points Moderator

2024-09-12T06:01:30.1566667+00:00

Kiran Krishnaji Patil,

That is not supported, GatewaySubnet is delegated to VNet Gateway and no other resource can be deployed into this.

EDIT

See : Configure route exchange

When you create or delete a route server in a virtual network that contains a virtual network gateway (ExpressRoute or VPN), expect downtime until the operation is complete. If you have an ExpressRoute circuit connected to the virtual network where you're creating or deleting the route server, the downtime doesn't affect the ExpressRoute circuit or its connections to other virtual networks.

Cheers,

Kapil
Anonymous

2024-09-12T06:12:04.24+00:00

Right Kapil, Route server will be deployed in separate dedicated subnet 'RouteServerSubnet'. Thank you for clarifying my query about downtime.

Thanks,

Kiran
KapilAnanth 49,876 Reputation points Moderator

2024-09-12T15:33:53+00:00

Kiran Krishnaji Patil,

You are welcome.

I have updated my previous comment wrt Downtime.

Please review it once again.

Apologies for the edit.

Cheers,

Kapil
Anonymous

2024-10-25T05:36:33.3+00:00

Thank you @KapilAnanth . We successfully implemented Route server with Downtime taken
KapilAnanth 49,876 Reputation points Moderator

2024-10-25T05:41:40.07+00:00

Kiran Krishnaji Patil,

I'm glad that you were able to deploy the RouteServer.

Thanks for your continued contribution on Q&A and appreciate much for taking the time to share your feedback

Cheers,

Kapil