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My Hyper-V host has two physical NICs; I've been running my VMs on one of them successfully for quite some time now.

I now have attached a NAS device to the second NIC. I followed the tip provided by longneck here, but unfortunately the NIC speed in the NAS steps down to the lowest common denominator—the older 10/100 switch that connects the host with the workstations.

So I've opted for #1 in his second tip, here. As anticipated, this enables me to connect to the NAS from the VM. However, the NAS can't connect to the Internet to receive OS updates, send email, etc.

At first I thought it might be due to multiple default gateways on the host, so I fixed that:

enter image description here

I also tried configuring a NAT network, as discussed here, and setting the gateway of NIC 2 to 192.168.3.1. But that requires multiple gateways on the host, so I probably shouldn't have expected it to work in any case. (And, since only a single NAT network is supported on a host, I had to temporarily remove my Docker NAT, a configuration I wouldn't have been pleased with.)

These are the NICs on the PDC VM:

enter image description here

The NAS can connect to the PDC VM and receive an IP configuration from DHCP:

enter image description here

I can ping the NAS from the host, as well as from the PDC VM:

enter image description here

192.168.2.1 is the LAN interface for our SOHO NAT router. I suspect this problem may have something to do with that—it's possible that the 192.168.3.0/24 subnet can't connect to the gateway for the 192.168.2.0/24 subnet.

Is this solved with something called 'routing?'

--EDIT--

I don't understand routing, although I did find a bit of an explanation here.

So I entered this command:

route ADD 192.168.3.0 MASK 255.255.255.0 192.168.2.1 IF 19

Here're the results:

    C:\Users\Admin>route print /4
===========================================================================
Interface List
  3...00 15 5d ea 3d 97 ......Hyper-V Virtual Ethernet Adapter #3
 19...54 9f 35 00 84 c0 ......Hyper-V Virtual Ethernet Adapter #2
  9...54 9f 35 00 84 be ......Hyper-V Virtual Ethernet Adapter
  1...........................Software Loopback Interface 1
 11...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
  7...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3
 35...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #4
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.2.1     192.168.2.11     36
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    331
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    331
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    331
      172.17.48.0    255.255.240.0         On-link       172.17.48.1    271
      172.17.48.1  255.255.255.255         On-link       172.17.48.1    271
    172.17.63.255  255.255.255.255         On-link       172.17.48.1    271
      192.168.2.0    255.255.255.0         On-link      192.168.2.11    291
     192.168.2.11  255.255.255.255         On-link      192.168.2.11    291
    192.168.2.255  255.255.255.255         On-link      192.168.2.11    291
     192.168.3.11  255.255.255.255         On-link      192.168.3.11    281
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    331
        224.0.0.0        240.0.0.0         On-link      192.168.2.11    291
        224.0.0.0        240.0.0.0         On-link       172.17.48.1    271
        224.0.0.0        240.0.0.0         On-link      192.168.3.11    281
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    331
  255.255.255.255  255.255.255.255         On-link      192.168.2.11    291
  255.255.255.255  255.255.255.255         On-link       172.17.48.1    271
  255.255.255.255  255.255.255.255         On-link      192.168.3.11    281
===========================================================================
Persistent Routes:
  Network Address          Netmask  Gateway Address  Metric
          0.0.0.0          0.0.0.0      192.168.2.1       1
===========================================================================

C:\Users\Admin>route ADD 192.168.3.0 MASK 255.255.255.0 192.168.2.1 IF 19
 OK!

C:\Users\Admin>route print /4
===========================================================================
Interface List
  3...00 15 5d ea 3d 97 ......Hyper-V Virtual Ethernet Adapter #3
 19...54 9f 35 00 84 c0 ......Hyper-V Virtual Ethernet Adapter #2
  9...54 9f 35 00 84 be ......Hyper-V Virtual Ethernet Adapter
  1...........................Software Loopback Interface 1
 11...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
  7...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3
 35...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #4
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.2.1     192.168.2.11     36
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    331
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    331
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    331
      172.17.48.0    255.255.240.0         On-link       172.17.48.1    271
      172.17.48.1  255.255.255.255         On-link       172.17.48.1    271
    172.17.63.255  255.255.255.255         On-link       172.17.48.1    271
      192.168.2.0    255.255.255.0         On-link      192.168.2.11    291
     192.168.2.11  255.255.255.255         On-link      192.168.2.11    291
    192.168.2.255  255.255.255.255         On-link      192.168.2.11    291
      192.168.3.0    255.255.255.0      192.168.2.1     192.168.3.11     26
     192.168.3.11  255.255.255.255         On-link      192.168.3.11    281
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    331
        224.0.0.0        240.0.0.0         On-link      192.168.2.11    291
        224.0.0.0        240.0.0.0         On-link       172.17.48.1    271
        224.0.0.0        240.0.0.0         On-link      192.168.3.11    281
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    331
  255.255.255.255  255.255.255.255         On-link      192.168.2.11    291
  255.255.255.255  255.255.255.255         On-link       172.17.48.1    271
  255.255.255.255  255.255.255.255         On-link      192.168.3.11    281
===========================================================================
Persistent Routes:
  Network Address          Netmask  Gateway Address  Metric
          0.0.0.0          0.0.0.0      192.168.2.1       1
===========================================================================

C:\Users\Admin>

But... still no success. My NAS still can't connect to the Internet.

--EDIT #2--

I should explain better what I mean when I say that the NAS 'steps down' to 10/100.

When I configure the cabling to include the Gb switch, as suggested by longneck here, the admin interface for the NAS reports bandwidth of 10/100. However, when I run a cable from the physical NIC on the Hyper-V host directly to the NIC on the NAS, the NAS reports Gb speeds:

enter image description here

(I'm not onsite, so I'm presently unable to reroute the cables to get a screen shot of the slower report.)

Also, note in the image above the reported speed of the disconnected eth1— 1Gbps. When the Gb switch is in place and I swap the cable from eth0 to eth1, the disconnected eth0 then shows 1Gpbs and the connected eth1 shows 10/100. I can only surmise that this has something to do with the slower 10/100 switch to which the 1Gpbs switch is connected via a separate cable.

I need Gb speeds on the NAS, so apparently this can't be done with cabling. For the meantime I've opted for his suggested software configuration; thus the 1Gpbs report above. (But under this configuration the NAS can't connect to the Internet, as described earlier.)

Here's the model 1Gpbs switch I'm using:

enter image description here

  • "switching to the lowest common denominator" isn't a thing. The nas has no way to know what port speed other devices have connected at. So either your nas is not as fast as you think it is, or your gigabit switch is junk. Or it's hooked up wrong. – longneck Jul 30 '17 at 11:21
  • Your subnets and IP addresses are all over the place. Do you understand subnets and routing? – longneck Jul 30 '17 at 11:23
  • @longneck — "The nas has no way to know what port speed other devices have connected at." That's what I'd thought as well—which is why I found the 'drop-down' so odd. See my 2nd edit for clarification. – InteXX Jul 31 '17 at 0:52
  • @longneck — "Your subnets and IP addresses are all over the place." Before this exercise, I had no idea that the route command even existed. I copied the command syntax from here, and modified it slightly to fit my network. I went by this paragraph's advice: So, for example, if you wanted to add a route specifying that all traffic bound for the 192.168.35.0 subnet went to a gateway at 192.168.0.2 and you just wanted to use the automatic metric cost, you would use the following command. – InteXX Jul 31 '17 at 0:57
  • @longneck — "Your subnets and IP addresses are all over the place." The first route print command output above (before I added my route) was the first time I'd ever run the command on my two-month-old clean install of Hyper-V 2016. Those other subnets and routes presumably were created by my Docker install. I didn't know what they even were, let alone that they were there, until I issued that first route print command. So no, I don't understand routing :-) But I do know what a subnet is. These things are why I'm asking for advice on this forum. I appreciate your patience and your help. – InteXX Jul 31 '17 at 1:02

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