Further to this, using TCPView I can see HP SUM establish a connection on 22 and then 5989 which are successful.
I have worked out why this is happening. In order to clear an erroneous Hardware Storage Status warning in vCenter I had installed the Recommended HP Update "* RECOMMENDED * HP Agentless Management Service Offline Bundle for VMware ESXi 5.x (American, International)". This replaced the hp-smx-provider vib with the hp-smx-limited vib, which clearly doesn't support HP SUM. Reverting to the hp-smx-limited vib restored HP SUM functionality, but also unfortunately restored the invalid warning message too.
Thanks for getting back to the community here, I am having the same problem with my ESXi 4.1 server running on HP BL 490c G7 and also the HP DL 380 G6-G7, even though they are using the HP customized ESXi image, it failed with the same error message when I'm trying to perform "inventory" to update the firmware.
However, the as soon as you upgraded to ESXi 5.1 Update 1 by using HP customized .ISO file it work straight away with no issue, HP SUM v6 (web based interface) can now talks and scans the firmware update needed.
The latest version of HP SUM 5.3.5 doesn't actually support ESXi 4.1 according to the HP support tech that I have been working with for the past two days on this issue. I also confirmed this through the "Custom Baseline" option in the SUM. (Only VMWare ESXi 5.0 and 5.1 are listed). So for now, I'm looking to upgrade to 5.x and then running SUM again. Unfortunately, when I went looking for earlier versions of SUM to try and downgrade to, even the link on the main Proliant tools site for HP SUM is broken. My hope is that this suggests that HP is aware of the issue and working to resolve.
Glad to hear that, which means that I'm not alone here :-)
That is somehow hard to believe, the reason for running HP SUM is obviously to perform Firmware upgrade which is the prerequisite of the ESXi upgrade from 4.1 into 5.1 or even 5.5, but in this case we are left stabbing in the dark when we perform the upgrade since we do not know which component needs to be updated first.
I am stuck in the upgrade process and manually researching the firmware release notes for each of the components in my HP Blade Servers.