CarlFitzs

Q: OSX Server v5.1 DHCP on - wrong DNS over wireless - Next up NTP

Background:

I have a mixed network of hardware devices consisting of Cisco router, switches, Apple Airport devices and a Cisco Aironet device. Presently I use a Mac Pro (Late 2013) with (as of 6-2016) Server 5.1.5 (3.7 GHz Quad-Core Intel Xeon E5 - 12 GB 1866 MHz DDR3 ECC, 10.11.5) to perform several network functions such as DNS, DHCP, Open Dir, VPN, Time Machine...

 

This network has been up and running in similar setup for almost a decade using two different Mac Mini (one replaced the other) as the Server and now the Mac Pro. I miss the XServe and have struggled to keep an Apple product as the main Server for the network several times being in the process to use Cisco or worst yet other.

 

I have a mixed hardware environment of Microsoft, Rasp II, Linux Servers and Apple. The XServe was freakin awesome and being heavily into network and telecommunications the server is really where all things get connected for an organization. So if your Server(s) are not MAC then it is a struggle. Even at least if an Apple server were comparable to Enterprise servers such as the XServe was.  Ok enough but heres asking Apple to get back into it as there is a good base already.

 

There was a point in time I upgraded Server on the last Mac Mini that WiFi connected devices lost DNS address when the DHCP scope provided information when requested by the wireless client. The DNS value would not be pushed out and instead 127.0.0.1 was present and interestingly the secondary DNS IP was provided. So in the beginning of this problem with network devices being small I would set the DNS value as needed. Now we are adding more devices and setting manually is less desired plus it leaves a problem should we change the network.

 

I have been attempting for several years to find a solution - not full time. I have learned a lot about OSX Server. Read many articles on GUI and CLI settings. I found that OSX Server has a LOT of capability that is not present in the GUI and wish it were such as enabling other DHCP services and NTP setup to enable OSX Server to be the local network NTP Server and then have that pushed out to devices on the network when DHCP is requested.

 

Well I found the solution and it was staring me in the face all this time. Inside the bootpd.plist file was an entry I thought was suspicious early on but through Apple TAC I - we would not pay attention to this. So today I changed a value in the dhcp_domain_name_server array from 127.0.0.1. to the IP of the Server itself. After a few moments I refreshed the DHCP scope on the laptop or other wireless device and there it was. The 127.0.0.1 address for the 1st DNS server was replaced by the IP of the network Server.

 

Now I need to find out how to successfully push NTP out to devices using the DHCP request. This link while helpful http://blog.philippklaus.de/2012/11/setup-an-ntp-server-in-mac-os-x-10-8/ does not provide the solution or I do not fully understand what is in there.

 

If there is another location I should change the DHCP scope information for DNS and also how to send NTP information to a Client I would appreciate that information.

 

Thanks

Mac Pro, OS X El Capitan (10.11.5), Server 5.1.5

Posted on Jun 4, 2016 7:54 AM

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Q: OSX Server v5.1 DHCP on - wrong DNS over wireless - Next up NTP

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  • by John Lockwood,

    John Lockwood John Lockwood Jun 6, 2016 3:19 AM in response to CarlFitzs
    Level 6 (9,309 points)
    Servers Enterprise
    Jun 6, 2016 3:19 AM in response to CarlFitzs

    A Mac DHCP server can indeed 'advertise' the address of an NTP server this is done via DHCP option code 42 but Apple have a specific name for this DHCP option code of dhcp_network_time_protocol_servers unfortunately while the Mac DHCP server can advertise this value as far as I can see the Mac client does not listen for this field. As such it would seem you still have to manually configure the Macs. This can be done either in System Preferences, or via a script. If done via a script then this could be pushed over the network using Apple Remote Desktop Admin or other network tool.

     

    The one test I have not yet done is to have a client Mac with no NTP server defined and a DHCP server that as above pushes the value, and to then see if the Mac client picks it up. It certainly does not pick it up if as standard the Mac client already has a value defined. As default Macs use an Apple server.