LoadMaster LMOS 7.2.52 firmware feature enhancements

Let’s take a look at some of the recently released LoadMaster LMOS 7.2.52 firmware feature enhancements. You can read the release notes on their web site. Next to security updates there are two entries in the new features and change notices that caught my attention. The first is the new feature that delivers the Ability to use SNI in SubVS, as well as SNI-Hostname Pass-Through. Secondly, it is the enhancement that we can now configure Per-VS Health Check Settings. Both are very welcome as I have to deal with such scenarios or needs frequently. So let’s take a look.

Ability to use SNI in SubVS, as well as SNI-Hostname Pass-Through

The Server Name Indication (SNI) feature has been enhanced to support the following:

• The ability to pass through the original hostname as the SNI hostname to the Real Server.
• The ability to specify a different (manual) SNI hostname per SubVS. This is the same as the previous functionality to specify this on the parent Virtual Service (Reencryption SNI Hostname) but on the SubVS level with content switching.

These new features help make scenarios, where you may want to consolidate as many services as possible to the least amount of IP addresses, easier and less confusing to implement.

The Pass-through SNI hostname check box is available in the SSL Properties section of the Virtual Service modify screen. When this is enabled and when re-encrypting, the received SNI hostname is passed through as the SNI to be used to connect to the Real Server. If the Virtual Server has a Reencryption SNI Hostname set, this overrides the received SNI.

It is also possible to set the re-encryption SNI hostname in a SubVS (in the Basic Properties section). If it is set in a SubVS, this overrides the parent Virtual Service value and/or the received SNI value.

Per-VS Health Check Settings

Until now, health check settings were global-only, located on the Rule & Checking > Check Parameters UI page: Check Interval, Connect Timeout, and Retry Count

Now, we can also configure these settings on the Virtual Service Real Servers tab. This means we can tune the health check behavior for specific VSs and SubVSs. By default, real server health checks use the global settings. The VS or SubVS settings change as the global settings change. So the default behaves as in previous releases.

Once you change a check parameter on a VS or SubVS level, however, those custom VS or SubVS settings will remain unchanged regardless of changes made to the global setting. The UI indicates whether the currently in-use value is the global value or is set to a custom value.

Conclusion

I am really happy with the enhancements that are introduced with FW 7.2.52. The two I highlighted above are the ones I really come up against in the future. Not having a re-encryption SNI hostname on the SubVS level was something we could workaround (see How to Re-Encrypt Multiple SNIs on the Same IP and Port with Kemp LoadMaster – PART 1 and How to Re-Encrypt Multiple SNIs on the same IP and port with a Kemp LoadMaster – PART 2). But having this feature on the subVS makes life a lot easier.

Being able to set the real server health check interval, timeout, and retry count helps us in those scenarios where we have services with different needs. These global setting where always a balancing act between all the services. So this capability is very welcome as well.

It is great to see Kemp Technologies their offerings evolve and improve. They have established themselves quite well over the years. It makes me happy that way back I chose them for their price/value and excellent support. I still remember the first HA pair (LM-2200) I ever deployed (2011) for a real time reference GPS position system. That was the beginning of a very succesful journey building solutions with LoadMasters using both physical and virtual appliances.