Unable to Mount ISO Virtual Media over IPMI/iKVM Viewer

I have a single Supermicro Host that has just gone into colo with dedicated IPMI.

I have assigned it a static internet facing IP for remote management. I have configured the IPMI to only be accessible from 2 IPs (Office dedicated + VPN) and the datacenter lets me nullroute the IP myself when not in use - so its not really "internet facing." Web Interface works fine, and allows me access bios level KVM, monitor hardware etcetera.

I'm trying to install the operating system remotely by Mounting an ISO using its built in Console Redirect. The console itself works but attempting to mount virtual media just outputs the following:

Device 1 :Can not connect to Server!!

Device 2 :Can not connect to Server!!

Device 3 :Can not connect to Server!!

And the ISO doesn't mount. I've also tried connecting with IPMIView and this doesn't even detect the IPMI is up (it is, since web interface works). I should have successfully opened Port 623 (virtual media) on both my desktop firewall and my router.

Has anyone seen this before? Google wasn't helpful and the error message is very vague - hoping its not something really simple i'm missing!

I have found the answer for this. Timothy Frew's answer before me helped point me in the right direction.

Port 623/UDP is the standard IPMI port. Port 623/TCP is supermicro's Default Virtual Media Port on this BMC.

This is rather silly of SMC, as port 623/UDP is a known attack vector, and I would expect it to be restricted.

My data center (wisely) are filtering traffic on port 623 which I discovered when tracing the route/scanning the ports. So it wasn't my firewall or configuration but the DC's on their own IP network. I was able to fix this by changing the default port from 623 to another port, but IPMIview obviously still doesn't work (however, I now realise the problem). In Dell and HPE's out of band, they use a different port.

You can change the default ports in the web GUI for added obscurity and to get around issues like this.

It should have been obvious but like most things, only after you've found the solution.

Be aware that you’ll need to allow a variety of ports for this on the firewall. Different functions require different ports to be opened up, especially for mounting media.

Check supermicros documentation on what these ports are