Windows Failover Cluster support in single subnet


I am testing one of our apps on EC2 instances. This app runs in a MS WSFC arrangement. Our bare-metal & HyperV deployments use two different interfaces, each interface in its own subnet, with each node in those subnets.
When i built out the new subnets & interfaces in the VPC, i mirrored this. But when trying to build the cluster on EC2's i keep receiving a generic error about RPC. I went back to my own HyperV & did the same procedure, & it works. It seems it is something specific to the VPC &/or EC2. Has anyone been able to get this arrangement to work?

2 Answers


I do not see the error message , can you please make sure you have allowed all the connection for RPC communication in the security of group of both the instances.

Please refer this document, hope this helps.

Multi-region SQL Server deployment using distributed availability groups

Service overview and network port requirements for Windows

SQL Server Failover Cluster Instance on AWS

if you still face the issue, open support ticket or share us with more details.

answered 2 years ago

Thank you. I believe i have all the needed ports opened: TCP 49152 - 65535 UDP 49152 - 65535 TCP 445 UDP 3343 UDP 137 - 138 ICMP All TCP 3343 TCP 135

The issue I am seeing is the server is not listening on the needed cluster port because the cluster service refuses to start. I found this in an AWS SQL Cluster AAG setup guide: "Implementing a WSFC cluster in the AWS cloud, which is a prerequisite for deploying an AlwaysOn Availability Group, is not different from deploying both technologies in an on-premise setting as long as you meet two key requirements:  You must deploy the cluster nodes inside a VPC.  You must deploy WSFC cluster nodes in separate subnets."

I am deploying the WSFC cluster nodes in the same subnet. But I do not know why this would not be supported. I have deployed numerous WSFC clusters at sites where they are in the same subnets.

answered 2 years ago

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