Uniti Core / DHCP

passed to technical support

Hello,

an update – brought the Core from my office (my unboxing location) home. Different network – same issue. Called the dealer: same issue there. They called the German distributor which opened a ticked on this.

Furthermore two sub-issues: when un-checking the DHCP the next screen shows the network credentials. In all cases the subnet mask represents faulty values (255.0.0.0 instead of 255.255.255.0) – no idea if this causes any (other issues). In addition the two  DNS servers are showing up with the ONE value only. In my office we have two DNS servers and the Core picks only one of them but shows them in both lines. At home the Core puts in my one and only DNS server in both lines. Just to make sure I have even factory reset the Core both at home and in the office – plus I have reset the Naim app (iOS) and even uninstalled and reinstalled it...

Should be investigated.

Best, Lorenz

Agree with Lorenz, I get exactly the same issue, plus as he says a net mask of 255.0.0.0 is a Class A network of 16,777,214 possible devices, a shade more than the average household? 

I can get round it by setting  a MAC to ip address but not all routers will allow this.

Nothing wrong with 255.0.0.0 on the address range 10.x.x.x

Could you elaborate?

I'm not sure what needs elaborating if you understand addressing and subnet masks? It is what it is?

jon honeyball posted:

Nothing wrong with 255.0.0.0 on the address range 10.x.x.x

Jon is absolutely correct - on a class A private network the subnet mask of 255.0.0.0 on a 10.0.0.0 network is completely valid and  is exactly the *correct* subnet mask you need to  use for a subnet of of 16,777,214 hosts, which is the *largest* subnet you can use on a class A network. You would see this network typically written  as 10.0.0.0/8, and the hosts in this large subnet would have addresses within 10.X.X.X (excluding 10.0.0.0 and 10.255.255.255)

I could also use a class A network and create a smaller subnet within it - which is typically what you do in real commercial networks -  so  I could also create a network address of 10.0.0.0/24 which equates to a subnet mask of 255.255.255.0 and so my subnet would support 254 hosts, and so the network addresses of my hosts within this network   would look like 10.0.0.X, (exc 10.0.0.0 and 10.0.0.255) or if my class A network address looked like 10.2.3.0/24 (i.e. subnet mask of 255.255.255.0) my subnet hosts would have addresses 10.2.3.X (exc 10.2.3.0 and 10.2.3.255) and again I can have upto 254 hosts.

Quite so. Only thing I would add is that the concept of a class a class b class c addressing is somewhat quaint now. 

Jon, that I don't agree with, when designing private address spaces, managing the different class a b c and of course d networks is important, and the differentiation between them is important. For example a customer by design may well have address ranges mapped to class a and class c networks where class c can be used for small remote sites and facilities, and class b networks by specifically used for management loop back addresses for complete non over lapping separation. Having the different private classes clearly identified with different network addresse prefixes can also help with summarisation of internal routing designs, so as to reduce prefixes in router routing tables  and to reduce complexity as well as making maintenance and changes easier to administer.  Also for private addressing only certain class a, b or c addresses are valid so as not to overlap and clash with public internet addresses.

Yes for the external public internet addresses, which might be what you were thinking of, then class based addressing has effectively given way to other considerations.

192.168 has turned into a domestic hell of double nat and other horrors

i note that the new norton security unit for home uses the private 172 range which is interesting 

Jon why on earth are you using double nat? .. an horrendous kludge, if you need ,multiple class c subnets use a proper router to route between then, but I would have thought for the vast majority 254 hosts on a home network is more than ample.... and even running a subnet mask of 255.255.255.192 giving 62 hosts is typically fine.. and indeed I have done that when required at home...

Yes class b addresses are fine and of course can support larger subnets of hosts with the largest subnet supporting 65534 hosts which I suspect is more than a home network will ever need  , Apple routers typically let you select class a, b or c (10.x.x.x, 172.16.x.x or 192.168.x.x) when setting up the internal address space and the dhcp scope, but only typically support a 255.255.255.0 subnet mask.

I am not using double nat!!!! Wash your mouth out dear sir

the issue is people adding wifi routers to existing networks and ending up with a disaster. 

Back to 255.0.0.0...

Probably reporting back the subnet mask as 255.0.0.0 with the Naim App might be "legal" (in IT definitions) - it still makes me worry and it does make narrowing issues more difficult...

Router at home explicitly serves 255.255.255.0 and ALL other devices read it as this - even ALL my other Naim boxes installed. Currently my muso, muso QB and the 272 report 255.255.255.0 back to either their display (272) or via their web interface (muso and muso QB).

Not sure if this is connected to the more severe issue that I'm unable to turn off DHCP as it does not save the setting - this issue should be solved for consistency (even if it might be "legal" and is only cosmetic)...

Oh dear, everyone (apart from Lorenz)  seems to have completely missed the point of our original posts. 

I agree that a Class A or 255.0.0.0 mask will work, it's that no router or switch manufacturer I've seen since 1980 sets a subnet of anything other than the default of 255.255.255.0 regardless of the private ip range of 10.0… or 176. or 192. 

We have used a 255.255.0.0 where we needed a larger number of machines on one side of a router, but lately it's much better to employ separate VLANS and intelligent routing via Layer 3 or 4 switches.

As anyone that has setup a campus wide network will know, the idea of a small (255 devices) is the preferred way to stop a possible broadcast storm.

I shall carry one setting up all our switches and routers with a 255.255.255.0 subnet until CISCO, HP etc. tell me different!

"I agree that a Class A or 255.0.0.0 mask will work, it's that no router or switch manufacturer I've seen since 1980 sets a subnet of anything other than the default of 255.255.255.0 regardless of the private ip range of 10.0… or 176. or 192. "

I have seen and tested numerous of them that do. 

Lorenz posted:

Back to 255.0.0.0...

Probably reporting back the subnet mask as 255.0.0.0 with the Naim App might be "legal" (in IT definitions) - it still makes me worry and it does make narrowing issues more difficult...

Router at home explicitly serves 255.255.255.0 and ALL other devices read it as this - even ALL my other Naim boxes installed. Currently my muso, muso QB and the 272 report 255.255.255.0 back to either their display (272) or via their web interface (muso and muso QB).

Not sure if this is connected to the more severe issue that I'm unable to turn off DHCP as it does not save the setting - this issue should be solved for consistency (even if it might be "legal" and is only cosmetic)...

Lorenz - sorry i have no idea what you are suggesting? Subnet masks are simply a way to define a  network address and effectively the size of the network subnet ... all this does effectively for a host is tell it what the network broadcast address is and when to address packets to your gateway router or not

Anyway if there is a UI issue on the Core, Naim will address - but those network addresses you described were valid and not faulty as per your initial post... and I have said before on this forum another reason to use DHCP so you don't have to worry about this... let alone understand it.

Mike R posted:

I agree that a Class A or 255.0.0.0 mask will work, it's that no router or switch manufacturer I've seen since 1980 sets a subnet of anything other than the default of 255.255.255.0 regardless of the private ip range of 10.0… or 176. or 192. 

 

With respect this is absolute twaddle .. unless you are merely referring to basic plug and play  consumer home 'routers' which  often use 254 host subnets because its simpler as  they have very limited functionality in offering a single subnet off the internet and so used in basic environments and so not really intended to be used in commercial or professional networks... but move out of basic/simple home networks with a simple routed subnet off the internet its very different and there are no default subnets...... Its also worth noting many cheap home consumer routers  (DLINK, Netgear Asus etc) might  have a single 254 host subnet but their DHCP scopes are often smaller such as 64 addresses because of performance limitations.

BTW switches don't care about IP addresses and network addresses  - they leave that to the router, switches work with layer 2  MAC addresses.

S

UPDATE (after yesterday's updates (firmware App 1.2.5798.0.0. Root FS 1.2.1180.0.0 Boot Loader 1.1.1026.0.0 / iOS App 5.3 build 50302).

The newest updates removed the GREEN button "DHCP" per default. The Icon is GRAY (like deactivated) although DHCP works as I can see from either the app (Info) or any network scanner like Fing.

If I tick the gray DHCP in order th set/verify settings, I see an network credential page with empty fields only. Before the update the credentials were filled (with the ("faulty") 255.0.0.0 entry mentioned before in this thread). Now all is empty.

If I enter credentials manually they will be "saved" (with a warning that the Core might be unreachable when anything is wrong). When I re-reach /re-enter) the Network credential page ALL entries are "Invalid" although the Core can be reached from from the app or a network scanner like Fing.