Easy networking problem

[John Gray]

I wish to connect a gigabit PCIe ethernet card in a PC directly to a NAS box, using an ordinary Cat5e ethernet patch cable (not crossover). I understand that the NAS will support this connection mechanism.

There is already a NIC built-in to the PC motherboard for connection to the (slower) LAN, which can be ignored for the purposes of this question.

PC ethernet card IPv4 address: 192.168.123.1
PC ethernet card Subnet Mask: 255.255.255.252
PC ethernet card Default Gateway: ?.?.?.? or absent?

NAS ethernet port IPv4 address: 192.168.123.2
NAS ethernet port Subnet Mask: 255.255.255.252
NAS ethernet port Default Gateway: ?.?.?.? or absent?

I am not clear what to specify as the Default Gateway field in both the PC ethernet card and the NAS.

[I know someone will suggest "why don't you try it?" but the NAS is currently in use, and I would need it to work first time without having to faff around when moved and reconfigured...!]

[StuartR]

John,

You need to specify a default gateway on the network card that connects you to the Internet. This will normally be done for you by the DHCP server software in your router. I can see that you have a very narrow subnet mask on this address, have you configured that on the router, or just on the PC? Do you not have any other devices on your network? Even so the subnet mask of 255.255.255.252 will include the address 192.168.123.2, which is not on that network.

I suggest giving the NAS ethernet card an IP address that is completely different, maybe you could use 10.1.1.1 for that, and 10.1.1.2 for the NAS box. To find valid addresses for private networks you can use your favourite search engine to look up "Private IP address ranges"

[John Gray]

Thanks, Stuart - but I have said that the motherboard ethernet NIC which connects to the internet can be ignored (the IP address is on a completely separate network range, and works wonderfully!).

Do I gather from what you say that my little PCIe card/NAS subnet doesn't need a default gateway address (other than 0.0.0.0)?

[StuartR]

Ah, I understand now John. There is no need to specify a default gateway on this subnet, because you only want packets to local network addresses sent this way.

When you have everything connected you can use the DOS command ROUTE PRINT to check that everything is set up correctly. This will show you what route will be taken to each possible IP address, it's a little tricky to interpret but let us know if you need help.

ALSO please confirm that your other network card is NOT using an address in the 192.168.x.x range. If it is then I still think you should renumber this one to 10.x.x.x

[John Gray]

Thanks, Stuart!

I use ROUTE PRINT -4 quite a lot for our various servers, and I agree that the output is complex. I inspect that subset of the results which look relevant to me.

Yes, the motherboard NIC is on our 10.40.129 subnet.

I'm hoping all will go well when I try this!

[StuartR]

Although I agree that a subnet mask of 255.255.255.252 should work, it provides exactly two usable IP addresses on that subnet. Unless there is a very good reason I would generally go for 255.255.255.0 to provide a little more flexibility.

[John Gray]

There will only be those two devices on the subnet. Surely .3 would also be available (not that it's wanted)?

[StuartR]

With that subnet mask, .3 would be a broadcast address

[John Gray]

Ah - hadn't realised that! I was only using 255.255.255.252 because I had never used it before!

[StuartR]

It's perfectly valid, for a subnet with exactly two hosts.

[John Gray]

Referring to my initial post about putting a NAS box on a separate network and thus network card, I have AT LAST had an opportunity to try it, and almost everything works as expected.

Adapter Settings for the add-in PCIe ethernet NIC shows "Unidentified Network" when the connection is enabled with the card connected to the NAs via a straight-through ethernet patch cable, but I suppose that is to be expected.

It's possible to PING both the ethernet card and the NAS, make a NET USE connection to the NAS's share, and view the folders and files on the share.

The only thing I can't get to work is to enable the NAS to access the internet to detect whether any updates are needed for the NAS software.
I have tried putting in the address of the NIC (192.168.123.1) as the default gateway, and leaving it blank, but neither setting works (the second one not surprisingly!).

Will I need to set up a static route to get from the 192.168.123.0 network (PCIe ethernet NIC) to the main LAN on 10.40.129.0 (motherboard NIC)?
I'm guessing
ROUTE ADD -p -4 192.168.123.0 MASK 255.255.255.0 [or 252?] 10.40.129.253 [router address]

[StuartR]

I don't think you can use a non-server version of windows to do this. You need the IP stack on the PC to act as a router, moving packets between the two networks. On a Windows server you can set this up with NETSH FORWARDING=ENABLED, but I don't think you can do it on a user PC.

[StuartR]

I've not tried this, but here are instructions for enabling routing and remote access on Windows 10
http://www.keepthetech.com/2016/01/enab ... ows10.html

[John Gray]

Thanks, Stuart - in fact the PC runs WS2008 R2 SP1 ! (It's an HP Compaq Elite 8300.)

I will investigate both mechanisms on Sunday...

LATER - I find that NETSH FORWARDING is not available on WS2008R2.

[StuartR]

Thanks, Stuart - in fact the PC runs WS2008 R2 SP1 ! (It's an HP Compaq Elite 8300.)

Here are instructions for how to configure LAN Routing on that version...
http://www.itgeared.com/articles/1343-e ... s-2008-r2/

[John Gray]

Fantastic! I shall try this on Sunday, rain permitting...!

[John Gray]

It didn't work! I went through all the steps, but still with no apparent internet connection from the 123 subnet. I forgot to try my 'static route', also.

I found a number of almost identical writeups the same as the one you suggested, but this one goes rather further (starting at point 8).
I have no idea whether this has any relevance to what I want to achieve - what do you think?

[StuartR]

That looks about right to me. I suspect you want NAT at step 9, rather than RIP V2, but it is years since I last did this. Try both and see what happens.

When you have configured it, do you see that the RRAS service is running?

[John Gray]

Thanks, Stuart - I chose NAT and thence the two LAN interfaces, assigning them to Public and Private respectively, and the Synology NAS connection to the internet to check on versions of DSM and download updates now works immediately!

The RRAS service was one of the first things that I started, and I note that the Start type is now set to 'Automatic (delayed)' rather than the 'Automatic' to which I had set it originally.

Again thanks - I wouldn't have got anywhere without your networking knowledge!

[StuartR]

Thanks for the update. I'm glad you got that sorted.