Speeding Up Failover Tips-n-Tricks

From time-to-time people ask me for suggestions on what tweaks they can do to make Windows server Failover Cluster failover faster. In this blog I’ll discuss a few tips-n-tricks.

  1. Disable NetBIOS over TCP/IP – Unless you need legacy OS compatibility, NetBIOS is doing you nothing but slow you down.  You want to disable NetBIOS in a couple different places:
    1. Every Cluster IP Address resources – Here is the syntax (again, this needs to be set on all IP Address resources).  Note: NetBIOS is disabled on all Cluster IP Addresses in Windows Server 2016 by default.
      Get-ClusterResource “Cluster IP address” | Set-ClusterParameter EnableNetBIOS 0
    2. Base Network Interfaces – In the Advanced TCP/IP Settings, go to the WINS tab, and select “Disable NetBIOS over TCP/IP.  This needs to be done on every network interface.
      NetBIOS
  2. Go Pure IPv6 – Going pure IPv6 will give faster failover as a result of optimizations in how Duplication Address Detection (DAD) works in the TCP/IP stack.
  3. Avoid IPSec on Servers – Internet Protocol Security (IPsec) is a great security feature, especially for client scenarios. But it comes at a cost, and really should not be used on servers. Specifically enabling a single IPSec policy will reduce overall network performance by ~30% and significantly delay failover times.

A few things I’ve found you can do to speed up failover and reduce downtime.

Thanks!
Elden Christensen
Principal PM Manager
High-Availability & Storage
Microsoft