Available to Windows 10 Insiders Today: Access to published container ports via “localhost”/

Until now, a lingering limitation on Windows 10 has prevented access to published ports for containers via “localhost” or (a.k.a. loopback). What this meant, was that if you had, say, a container running as an IIS Web server and exposing content through port 80 of your host machine, you wouldn’t be able to access… Read more

SDN Troubleshooting: UDP Communication failures and changing the Network Controller Certificate

With this blog post, I wanted to highlight a couple of issues that we have encountered recently with Software Defined Networking (SDN) customer deployments in Windows Server 2016. Issue #1: UDP communication isn’t working when outbound NAT is configured Customer had configured outbound NAT access for his virtual network through SCVMM (this internally uses SDN… Read more

Core Network Stack Features in the Creators Update for Windows 10

By: Praveen Balasubramanian and Daniel Havey This blog is the sequel to our first Windows Core Networking features announcements post.  It describes the second wave of core networking features in the Windows Redstone series.  The first wave of features is described here: Announcing: New Transport Advancements in the Anniversary Update for Windows 10 and Windows… Read more

HTTPS Client Certificate Request freezes when the Server is handling a large PUT/POST Request

HTTPS Client Certificate Request freezes when the Server is handling a large PUT/POST Request   There is a class of problems that may occur when using client-side certificates in HTTPS. Sometimes, the server’s request for a client certificate will freeze (until the timeout of two minutes or so) when processing PUT/POST request with a large… Read more

Troubleshooting certificate issues in Software Defined Networking (SDN)

As you may be aware, Network Controller in Windows Server 2016 uses certificate based authentication for communicating with Hyper-V hosts and Software Load Balancer MUX virtual machines (VMs). Some SDN customers have complained about communication issues between Network Controller and hosts, although certificates were correctly configured on both the entities. On debugging, we found that… Read more

Windows network performance suffering from bad buffering

Daniel Havey, Praveen Balasubramanian Windows telemetry results have indicated that a significant number of data connections are using the SO_RCVBUF and/or the SO_SNDBUF winsock options to statically allocate TCP buffers. There are many websites that recommend setting the TCP buffers with these options in order to improve TCP performance. This is a myth. Using Winsock… Read more

Windows Networking for Kubernetes

A seismic shift is happening in the way applications are developed and deployed as we move from traditional three-tier software models running in VMs to “containerized” applications and micro-services deployed across a cluster of compute resources. Networking is a critical component in any distributed system and often requires higher-level orchestration and policy management systems to… Read more

How to find the SDN gateway local address for BGP peering in Windows Server 2016

A few days back, I wrote a blog post about some issues being faced by Software Defined Networking (SDN) customers. The issue was specific to changing VPN bandwidth settings in Windows Server 2016. You can read more about that issue and the solution here. Another area where we have seen customers struggle is finding out the… Read more

Troubleshoot Configuring SDN RAS Gateway VPN Bandwidth Settings in Virtual Machine Manager

I wanted to share some of my experiences with debugging Windows Server 2016 Software Defined Networking (SDN) related customer issues. These issues are related to SDN RAS Gateways.If you’ve deployed Software Defined Networking (SDN) in Windows Server 2016 Datacenter by using System Center Virtual Machine Manager (SCVMM), you might have encountered problems configuring the RAS Gateway… Read more