Server 2016 routing doesnt works

xiaohong ma 96 Reputation points

Hi all,
I googled a lot but no luck.
In my hyper v environment, I have only 1 VM with Server 2016 (ADDS, DNS and Remote Access) installed, the VM has 2 NICs, the internal NIC IP and external NIC IP which connect to my home's internet router (
After LAN routing configured the service started normally but not routed as expected.
The both NICs can ping each other (ping -S success and ping -S also success) BUT ping -S failed!
I'm a newbie I really don't know what is wrong! Please advise.

Windows Server
Windows Server
A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.
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  1. xiaohong ma 96 Reputation points

    Hi Sonny,

    Thank you very very much for your detailed explanation.
    I know the difference between NAT and Router:

    NAT--multiple private IPs share a public IP;
    Router--connect different subnets.

    I rebuilt the lab environment according to your post, but unfortunately, on RRAS, I still can’t ping between the 2 NICs, note: my Ping cmd with -S switch,

    Ping -S

    But once I set HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\IPEnableRouter to 1, I can ping between NICs without issue no matter RRAS installed or not.

    Ping -S

    Still failed.

    Then I configured "LAN Routing" on RRAS server, I CANNOT ping from DC to Windows 10 client, vice versa.

    Then funny thing happened:

    I connected all VMs in internal switch and set IPs as:

    IPv4 address
    Default Gateway
    RRAS server:
    IPv4 address
    IPv4 address
    Windows 10 client:
    IPv4 address
    Default Gateway

    Set IPEnableRouter to 1 and REMOVED RRAS, all VMs can ping each other!
    No matter how many subnets I added, the subnet can ping each other as long as IPEnableRouter set to 1 even without RRAS service.

    This is incredible! Microsoft drives me crazy!

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  1. xiaohong ma 96 Reputation points

    Hi DSPatrick,
    Thank you for your quick responding!
    I also tried it on a member server, same issue.

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  2. xiaohong ma 96 Reputation points

    I just wanted to make routing service works, see my initial post please, thanks.

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  3. xiaohong ma 96 Reputation points

    The article you mentioned is about NAT instead of Routing, NAT works but Routing doesnt.

    I'm not talking about above, I'm talking about below, thank you!



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  4. Sunny Qi 10,806 Reputation points Microsoft Vendor


    Thanks for posting in Q&A platform.

    Firstly, I noticed that DC has been configured as RRAS server, please kindly note that multihomed DCs are not recommended since they may cause much confusion and numerous errors may generate. AD, DNS and DHCP are the only roles considered acceptable to put on a DC under best practice.

    At current status, if you need subnet can ping subnet successfully, I would suggest you remove RRAS role from the DC&DNS server and create a new VM to host the RRAS role. The DC&DNS server needs to be configured with 1 NIC with IP subnet. The new RRAS server needs to be configured with 2 NICs, one is in subnet and another one is subnet Next please configure the RRAS NIC which is in subnet as DC&DNS server's default gateway. Now I think DC can ping your home's internet router successfully.

    Best Regards,


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