My ESXi 5.1 server Proliant DL 380 G5, hosts an Untangle 9.4 Appliance VM.
The VM has two network interfaces : the internal connected to vSwitch0 and the external connetcted to vSwitch 1 (that has a physical network card different from wich connected to vSwitch0 ).
All seems to works fine except this issue:
when I download a file from internet, it is downloaded to the full download speed available (about 400-500 kBps).
But, if I start a second file download, simultaneously to the first, I see that when the second download speed is about 350 kBps while the first drops drammatically to about 30-40 kbps.
The download speed in not equally reduced between the two files (I'll be expected 200-250 kbps for each file) and one is strongly reduced while the other not.
At this point I've shutted down the Appliance Untangle VM and connected to my LAN network a physical Untangle Appliance based on a server with less hardware resource than the virtual Untangle VM (less RAM, less CPU, etc...).
Repeating the same test I've seen results as I'll be expected: the downloads speed are reduced equally between the two files.
I've repeated many times the test with the same results.
At this point I thing that is anything ralated to the host ESXi and /or VM configuration.
I've tried, also, to set the vSwitch 0, 1 in "promiscuous mode" but the results where the same.
I've contacted UT support but he reject my request because thay don't support virtualizzation environments.
Thanks in advance.