When working with Hyper-V on Windows 8.1 Enterprise, administrators often notice that Windows VMs properly display their IP addresses in Hyper-V Manager, while Linux guests (particularly Debian-based systems) show blank fields. This occurs because:

• Hyper-V relies on the Hyper-V Integration Services (Linux IC) for IP detection
• The communication channel between Linux guests and Hyper-V host requires specific configurations
• Network adapter types and their drivers play a crucial role

Before diving into solutions, verify these fundamentals:

# Check Hyper-V integration services installation
lsmod | grep hv

# Expected output should show modules like:
# hv_utils                  
# hv_balloon               
# hv_netvsc                
# hv_storvsc

1. Install Hyper-V Integration Components

For Debian 8.x systems:

sudo apt-get update
sudo apt-get install hyperv-daemons
sudo systemctl restart hyperv-daemons

2. Configure Network Adapter Properly

In Hyper-V Manager:

• Remove existing network adapter from the VM
• Add new "Network Adapter" (NOT Legacy Network Adapter)
• Set VLAN ID if applicable

3. Verify Kernel Modules

After reboot, check active modules:

dmesg | grep -i hv

You should see successful initialization messages for Hyper-V components.

If integration services still don't report the IP, implement a fallback method by creating a custom script:

#!/bin/bash
# /usr/local/bin/report_ip_to_hyperv

IP=$(ip -4 addr show eth0 | grep -oP '(?<=inet\s)\d+(\.\d+){3}')
if [ -n "$IP" ]; then
    echo "$IP" > /var/lib/hyperv/ipconfig
    chmod 644 /var/lib/hyperv/ipconfig
fi

Then create a systemd service:

[Unit]
Description=Report IP to Hyper-V
After=network.target

[Service]
ExecStart=/usr/local/bin/report_ip_to_hyperv
Restart=on-failure

[Install]
WantedBy=multi-user.target

• Check Hyper-V host event logs for Linux IC errors
• Verify time synchronization between host and guest
• Test with a temporary firewall disable: sudo systemctl stop iptables
• Consider updating to a newer Linux kernel if using old versions

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When running Linux virtual machines (specifically Debian 8.2) on Windows 8.1 Enterprise using Hyper-V Manager, the IP addresses fail to appear in the VM connection window, while Windows VMs display this information correctly.

Hyper-V Manager retrieves IP information from guests through the Hyper-V Integration Services. For Windows VMs, this works out-of-the-box because:

• Integration components are built into the OS
• KVP (Key-Value Pair) exchange is fully supported

For Linux VMs, this requires:

1. Proper installation of Linux Integration Services (LIS)
2. Functioning KVP daemon
3. Correct network configuration

Here's how to resolve the IP visibility issue:

Step 1: Verify Integration Services

Check if LIS is properly installed:

lsmod | grep hv

You should see modules like hv_utils, hv_netvsc, hv_vmbus

Step 2: Configure KVP Daemon

For Debian-based systems:

sudo apt-get install hyperv-daemons
sudo systemctl enable hv-kvp-daemon
sudo systemctl start hv-kvp-daemon

Step 3: Network Adapter Configuration

Ensure your VM is using the synthetic network adapter (not legacy) and has DHCP enabled:

cat /etc/network/interfaces
# Should contain:
auto eth0
iface eth0 inet dhcp

If the above doesn't work, create a custom script to report the IP:

#!/bin/bash
IP=$(hostname -I | awk '{print $1}')
echo "IPAddress=$IP" > /var/lib/hyperv/.kvp_pool_0

Make it executable and run periodically via cron.

• Check Hyper-V event logs for KVP errors
• Verify the time synchronization between host and guest
• Test with a temporary Windows VM to confirm host functionality

The KVP exchange occurs every 5 seconds by default. If you're experiencing performance issues:

# To adjust polling interval (in milliseconds)
echo 10000 > /sys/bus/vmbus/drivers/hv_util/parameters/hv_kvp_poll