Windows server routing changes ICMP source addr

ScooterOC 1 Reputation point

My simple network consists of Linsys router, hyper-v host with 5 virtual networks in CIDDR space. I am trying to connect to VMs in one of the five hyper-v virtual networks, 1721.16.21.0/24 from a physical Win11 computer on my network.

Hyper-v host IP address is and has five virtual networks:
172. 16.21.0/24,,, and
IP Forwarding is enabled on all Hyper-v interfaces

I added static route G/W: to the Linksys router and to the physical computer and I thought the static routes on router and the physical Win10 computer at was all I needed to let me connect to VMs from my computer but not so quick.

To troubleshoot, I placed Wireshark on the physical computer at, the Hyper-v host ( and the VM (

The VM receives the ICMP from and returns the ICMP source and destination IP
When that ICMP packet gets to hyper-v, ICMP packet IP source is now instead of as expected.
I'd don't understand this topic well enough and hope to understand why the source address changed when it reached the vhost and how to configure OS to route correctly.

PS: I am not interested in RASS because I need packet routing, not NAT.

Windows Network
Windows Network
Windows: A family of Microsoft operating systems that run across personal computers, tablets, laptops, phones, internet of things devices, self-contained mixed reality headsets, large collaboration screens, and other devices.Network: A group of devices that communicate either wirelessly or via a physical connection.
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  1. Limitless Technology 43,231 Reputation points

    Hello there,

    Maybe you can use Traceroute, Ping, MTR, and PathPing network tools or utilities that use the ICMP protocol to perform testing to diagnose issues on a network and identify why the source changes.

    The TRACERT diagnostic utility determines the route to a destination by sending Internet Control Message Protocol (ICMP) echo packets to the destination. In these packets, TRACERT uses varying IP Time-To-Live (TTL) values.

    How to Use TRACERT to Troubleshoot TCP/IP Problems in Windows


    --If the reply is helpful, please Upvote and Accept it as an answer–

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