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– Unless you want to have >15 character names (Node / Cluster / Network Name) or have some Windows 3.11 for workgroups clients, NetBIOS is doing nothing but slow you down. You want to disable NetBIOS on:
   1. Every Cluster IP Address resources– Note: NetBIOS is disabled by default on Windows Server 2016. Here is the syntax (again, this needs to be set on all IP Address resources)
      1. 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.
      
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– IPSec is a great security feature, especially for client scenarios. But it comes at a cost, and really shouldn’t 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