GCP: No Network Access on additional virtual network interfaces

google-cloud-platformgoogle-compute-enginenetworkingvirtual-networkwindows-server-2016

I have a Windows Server 2016 instance running on Google Cloud Console. I added a few extra virtual NICs to try to improve my network speed. Particularly hoping to use overseas endpoints to wormhole my way to faster internet, or at least just team them together for a general boost. The default network interface continues to work fine, but the extra NICs just say "No network access". What did I miss, people?

Here's my GCP networking config:

GCP network interfaces

VPC networks

And here's what I see from inside the VM:

Network and Sharing Centre

And here's my ipconfig:

Windows IP Configuration

   Host Name . . . . . . . . . . . . : xxxxxxx
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : xxx.local
                                       c.harvest316.internal

PPP adapter SonicWall NetExtender:

   Connection-specific DNS Suffix  . : xxx.local
   Description . . . . . . . . . . . : SonicWall NetExtender
   Physical Address. . . . . . . . . :
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 192.168.10.84(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.255
   Default Gateway . . . . . . . . . :
   DNS Servers . . . . . . . . . . . : 10.2.x.x
                                       192.168.x.x
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Ethernet:

   Connection-specific DNS Suffix  . : c.harvest316.internal
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter
   Physical Address. . . . . . . . . : XX-XX-0A-98-00-03
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.152.0.3(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.240.0
   Lease Obtained. . . . . . . . . . : Wednesday, 25 April 2018 2:28:45 PM
   Lease Expires . . . . . . . . . . : Thursday, 26 April 2018 2:28:45 PM
   Default Gateway . . . . . . . . . : 10.152.0.1
   DHCP Server . . . . . . . . . . . : 169.254.169.254
   DNS Servers . . . . . . . . . . . : 10.152.0.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Ethernet 2:

   Connection-specific DNS Suffix  . : c.harvest316.internal
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter #2
   Physical Address. . . . . . . . . : XX-XX-0A-01-00-02
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.1.0.2(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.240
   Lease Obtained. . . . . . . . . . : Wednesday, 25 April 2018 2:28:45 PM
   Lease Expires . . . . . . . . . . : Thursday, 26 April 2018 2:28:45 PM
   Default Gateway . . . . . . . . . :
   DHCP Server . . . . . . . . . . . : 169.254.169.254
   DNS Servers . . . . . . . . . . . : 10.1.0.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Ethernet 3:

   Connection-specific DNS Suffix  . : c.harvest316.internal
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter #3
   Physical Address. . . . . . . . . : XX-XX-0A-03-00-02
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.3.0.2(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.240
   Lease Obtained. . . . . . . . . . : Wednesday, 25 April 2018 2:28:45 PM
   Lease Expires . . . . . . . . . . : Thursday, 26 April 2018 2:28:45 PM
   Default Gateway . . . . . . . . . :
   DHCP Server . . . . . . . . . . . : 169.254.169.254
   DNS Servers . . . . . . . . . . . : 10.3.0.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Ethernet 4:

   Connection-specific DNS Suffix  . : c.harvest316.internal
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter #4
   Physical Address. . . . . . . . . : XX-XX-0A-04-00-02
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.4.0.2(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.240
   Lease Obtained. . . . . . . . . . : Wednesday, 25 April 2018 2:28:45 PM
   Lease Expires . . . . . . . . . . : Thursday, 26 April 2018 2:28:45 PM
   Default Gateway . . . . . . . . . :
   DHCP Server . . . . . . . . . . . : 169.254.169.254
   DNS Servers . . . . . . . . . . . : 10.4.0.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Ethernet 5:

   Connection-specific DNS Suffix  . : c.harvest316.internal
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter #5
   Physical Address. . . . . . . . . : XX-XX-0A-05-00-02
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.5.0.2(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.240
   Lease Obtained. . . . . . . . . . : Wednesday, 25 April 2018 2:28:45 PM
   Lease Expires . . . . . . . . . . : Thursday, 26 April 2018 2:28:45 PM
   Default Gateway . . . . . . . . . :
   DHCP Server . . . . . . . . . . . : 169.254.169.254
   DNS Servers . . . . . . . . . . . : 10.5.0.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

The SonicWall NetExtender VPN was fine before I added the extra NICs, and whether its connected or not doesn't change the other coin any way.

Best Answer

The reason this is happening is because you haven't provided the Windows machine with default gateway information. You need to add a default gateway for each new adaptor/interface.

So for an example, let's say you would like to add a default gateway for 'Ethernet 4' in your ipconfig output (this relates to the interface configured in GCP to use network 'cloudynet4').

If you look at your network page you can see that the gateway is stated as '10.4.0.1'.

You need to tell the Windows machine to use this address to send information to another network or the internet.

To do this, open a command prompt on the Windows machine with administraor priveldges, and then run the following coommand:

route add 0.0.0.0 mask 0.0.0.0 10.4.0.1 IF 4

To explain this command, this adds a route to all addresses outside of the network (i.e. the destination is 0.0.0.0), using gateway 10.4.0.1 and applies this to interface 4 (IF 4).

For each interface you would like to give internet access, you need to run this command (substituting the relevant gateway [retrieved from the networks page] and IF number for each interface [retrieved from the ipconfig output]).

Once, you have done this all of your interfaces will be alive and be able to send and retrieve internet traffic. You will be able to see the 'Default Gateway' section of the ipconfig output populate with the gateway IP address you have added.

For more information on adding routes in Windows please take a look here.