Set up Yosemite Server as a router/DHCP server with dual NIC adapters

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Level 1

20 points

Set up Yosemite Server as a router/DHCP server with dual NIC adapters

Hi,

I'm trying to replace my main router with OS X Server but I can't quite get it to work. My Server has two network adapters, one connects to an actual router that connects to the internet and the other one connects to the intranet. The problem is that I cannot make it to actually pass the internet connection to the intranet while assigning IP addresses. This is something every router does but I can't get my Mac to do it. I tried the Internet Sharing way on System Preferences but then I can't assign fixed IP addresses. OS X does automatic DHCP without possibility to edit the address pool or range.

I need my Mac to be between the networks and not a regular Server connected to another router as it was before because I need it to dial a VPN connection and share it on the Intranet while giving out fixed and disposable IP addresses. My old setup was like this:

******************************************************************************** ******************************************************************************** **********************

[Internet] — — — — [ISP-issued modem] — — — — [DSL dial-up router] — — — — [VPN link router] — — — — [DHCP router] — — — — [Intranet]

|

[OS X Server ]

******************************************************************************** ******************************************************************************** **********************

I have a dedicated VPN router to reduce each router's load and that way I can just easily turn the VPN link on and off as I please without messing with other stuff. DMZs are set in each router as are several rules to forward all traffic correctly. This worked with no issues at all.

Now I'm trying to set it up like this:

******************************************************************************** ******************************************************************************** **********************[Internet] — — — — [ISP-issued modem] — — — — [DSL dial-up router] — — — — [OS X Server] — — — — [Intranet]

******************************************************************************** ******************************************************************************** **********************

Effectively replacing the router that makes the VPN connection and the router that addresses IP distribution with just OS X Server. One DD-WRT or Ubiquiti router can actually replace everything from the Internet to the Intranet on my setup, and I have one of both but I want to use OS X Server and give OS X full control over my network. After digging around and reading several manuals for the software involved I did set up the second adapter to share the IP addresses from the pool on Server.app's DHCP tab but the internet connection won't jump over to the second adapter. As I stated before, I can just turn on Internet Sharing but then it doesn't assign fixed IP addresses or even the subnet. Right now I set up a temporal unsecured network to connect other devices besides the server to the internet while I try to fix this.

It looks like this:

******************************************************************************** ******************************************************************************** **********************[Internet] — — — — [ISP-issued modem] — — — — [DSL dial-up router] — — — — [OS X Server] — — X — — [Intranet]

|

( ( ( [Unsecured AP] ) ) )

******************************************************************************** ******************************************************************************** **********************

I had fun mapping stuff with text though. Anyway, If any of you know how to fix this I'd be grateful forever. I'm attaching screenshots of the configuration so you can point it out where I'm screwing it up.

Thanks again.

Posted on Apr 16, 2015 12:16 PM

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Answer 1

VitaPrimo® Author

Level 1

20 points

Apr 16, 2015 12:27 PM in response to VitaPrimo®

———SORRY, THE EDITOR SCREWED UP MY TEXT DOODLES———

Hi,

I'm trying to replace my main router with OS X Server but I can't quite get it to work. My Server has two network adapters, one connects to an actual router that connects to the internet and the other one connects to the intranet. The problem is that I cannot make it to actually pass the internet connection to the intranet while assigning IP addresses. This is something every router does but I can't get my Mac to do it. I tried the Internet Sharing way on System Preferences but then I can't assign fixed IP addresses. OS X does automatic DHCP without possibility to edit the address pool or range.

I need my Mac to be between the networks and not a regular Server connected to another router as it was before because I need it to dial a VPN connection and share it on the Intranet while giving out fixed and disposable IP addresses. My old setup was like this:

I have a dedicated VPN router to reduce each router's load and that way I can just easily turn the VPN link on and off as I please without messing with other stuff. DMZs are set in each router as are several rules to forward all traffic correctly. This worked with no issues at all.

Now I'm trying to set it up like this:

Effectively replacing the router that makes the VPN connection and the router that addresses IP distribution with just OS X Server. One DD-WRT or Ubiquiti router can actually replace everything from the Internet to the Intranet on my setup, and I have one of both but I want to use OS X Server and give OS X full control over my network. After digging around and reading several manuals for the software involved I did set up the second adapter to share the IP addresses from the pool on Server.app's DHCP tab but the internet connection won't jump over to the second adapter. As I stated before, I can just turn on Internet Sharing but then it doesn't assign fixed IP addresses or even the subnet. Right now I set up a temporal unsecured network to connect other devices besides the server to the internet while I try to fix this.

It looks like this:

I had fun mapping stuff with text though. Anyway, If any of you know how to fix this I'd be grateful forever. I'm attaching screenshots of the configuration so you can point it out where I'm screwing it up.

Thanks again.

Reply

Answer 2

Apr 16, 2015 2:44 PM in response to VitaPrimo®

I did this in the late 90's with my Amiga 3000T using Miami Deluxe as my TCP stack. Those were the days. 🙂

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Answer 3

VitaPrimo® Author

Level 1

20 points

Apr 16, 2015 3:24 PM in response to amiga1000

Oh god, I had to look that up. I was barely a teenager in the late 90s, now I lie from time to time and tell I didn't like the Spice Girls, it was a good time. However that doesn't solve my issue here. 😟

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Answer 4

Apr 16, 2015 3:29 PM in response to VitaPrimo®

lol, well if you used an Amiga 3000T I could tell you how to do it. 😁

I do not think the answer to you question is actually in the server software. I would set up Internet Sharing in the Sharing Preference panel. Once you get that working you can add the server stuff in afterward and set up the DNS and DHCP from the Server App.

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Answer 5

VitaPrimo® Author

Level 1

20 points

Apr 16, 2015 3:51 PM in response to amiga1000

The thing is that, on Server.app, the interface serving the Internet and DHCP becomes not available once Internet Sharing is turned on.
The computers connecting to the interface are served with IP addresses in the 192.168.2.0 subnet.

Even the area designated for networking at AppleCare couldn't help me, they elevated me two times until I was speaking to someone in English—my region is in Spanish.

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Answer 6

Apr 16, 2015 3:56 PM in response to VitaPrimo®

hm... then I can not really help much.

May I ask why you need it set up this way? If you route all traffic to your server by setting it up in a DMZ zone, you can then provide DNS and DHCP to the rest of the network.

I believe then all you need to do is set up routing in DNS. I have never tried it, but that sounds like a way to start.

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Answer 7

VitaPrimo® Author

Level 1

20 points

Apr 16, 2015 4:20 PM in response to amiga1000

I connect to several VPN providers and sometimes a router can't make a connection because of some parameter on a remote server. OS X always connects, and in any protocol, what's more, it can switch on the fly and be controlled via access easily on the Finder via Screen Sharing. I remember in previous versions that it specifically asked for two network adapters, now that's gone. I guess I could try downgrading my oldest Mac, setting it up then upgrading it back to Yosemite to see how the Settings migrated but it seems like such a hassle: my oldest Mac is a huge iMac (as newer Macs cannot be downgraded from the OS they came with) and the network closet is not the biggest of spaces. Also, I could just buy a cheap Windows box and tinker with it.

Thanks for your help though.

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Answer 8

Yonko

Level 1

0 points

Apr 20, 2015 8:14 PM in response to VitaPrimo®

Try switching the adapters' roles. Make the USB Thunderbolt the LAN side and the Built-in LAN adapter the WAN side. Check the LAN side's permissions for DNS requests etc. Add the forwarding servers to the DNS service. Perform lookups for server itself and LAN side clients.

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