What would cause me to be Unable to Ping or Remote to Dell R40 Hyper-v Host, but able to Reach Hosted VMs

Networking configuration on the host.

You need to logon to the host and at the console check host networking

in the vswitchs you need to enable share interface with host on at least one of the nics.  otherwise you will lose connectivity to the host but retain it to the vm's.  (I have done that tons of times :) )

Networking in Hyper-v is different than most people think.  There are one or more virtual switches in the hyper-visor and the "host" is just another OS.   It needs a physical adapter with an IP address or a virtual adapter "plugged in" to a virtual switch. And the host firewall won't impact VMs so the host firewall can be configured to block ICMP and RDP while guests would work just fine.

Thanks for your comments and quick response.

@Cliff Galiher - I have no firewalls turned on. And nothing based on any config that I have done over the past week has changed. And previously I was able to remote to the host Just fine.

@Sean Bravener - I am already allowing the management OS to share the network adapter

@Andrew - where would I check for host networking?

log in to the physical host hyper-v server  (ctrl-alt-del).

and check Control Panel > Networking.

Do you know how this Hyper-V server is configured ?

Team,

Sorry for the delayed response.

I had as a last resort before trying any of the above suggestions, I did a reboot of the server and that resolved the problem.