So am I!

@Corry P I have unpowered/rebooted all devices in the necessary sequences, no joy. Done it twice.

To the quoted, my set up is like this because the ISP UI is clunky: I have disabled the wireless on the ISP, wired a LAN jack on it to a TP Link router set up as an AP, with DHCP disabled there, but with WiFi on for both bands. I can manage the TP via a neat app. TP also feeds Sonos via wired connections besides putting out WiFi.

I wonder if I just need to disable DHCP on the ISP router, and enable it on TP link, and get much better UI to do reservations without having to muck around with other settings, esp in the ISP router, that I am not familiar with.

Will this work? But I suspect it will need so more tinkering in both ISP and TP Link, and my network setup up skills are severely limited.

Or, just let sleeping dogs lie till one starts barking? Discretion the better part of valour and all that.

Hi @Kumar 

You already have a secondary router? OK, I was not aware. That’s what I would do, yes - you’ve bought another router because you know the ISP one is poor, but it’s still technically doing all the routing - your new TP Link router is just acting as a network switch and WAP (Wireless Access Point) at this point. I would like to think the TP Link will behave as expected in regards to your reserved addresses and the address pool, unlike your ISP router (I have a TP Link router too and it’s great wee thing). You want the ISP router to be doing nothing other than providing an internet connection (assuming the TP Link router can’t do this on it’s own).

You are correct in saying that there should only ever be one DHCP server on your network at any one time - be sure to disable one while you enable the other.

That’s a choice I leave to you - networking can be a pain at the best of times. Learning a new skill can be rewarding, however - and not just in terms of improving your network.

I hope this helps.

Thank you. I am sure the TP Link can connect to the net and I can throw away the ISP router, but I suspect the ISP staff will have to involved in some tinkering so I don’t want to go down that road, also because in future if it isn't their router that gives any trouble, that gang will throw up its hands.

Yes new skills are good to have and I am much better off after Sonos use for ten years. Ten years ago all I knew was how to apply mains power to routers! But for now, with Sonos working fine as is all other kit, I shall leave well alone.

Thanks again.

Hi @Kumar

Ironically, my router stopped giving me internet later that day. I found that if I connected my ISP-provided router to my fiber-ethernet converter, that worked, so I ended up configuring it to have static IPs (for non-Sonos devices, but that’s not particularly relevant) and found that unlike my TP-Link router and like yours, I had to reserve IPs that were within the DHCP pool range. As I hadn’t recorded my MAC addresses, it was a bit of a pain to figure out what was what.

So, it does indeed depend on the brand of router whether or not you can reserve IP addresses inside or outside the pool range. It doesn’t help when it comes to providing advice, unfortunately. There is another, related thread where the difference between reserved IPs and static IPs is explained well:

When I called my ISP the next day, there was a bit of a queue, so as I waited, I tried my TP-Link again and it worked, so I hung up and got rid of the ISP router again.

Logically it does not make much sense for a router to reserve IP addresses outside of the DHCP range that it is managing. I would check the router's documentation to make sure that this is supported.

Hi @buzz 

After the recent refresher I just got on the subject thanks to my ISP, I agree. Static IPs should be outside of the pool, and each client device should be configured to not use DHCP and to simply take it’s static IP. With reserved IPs, the client device has DHCP turned on and requests an IP - it’s the router that remembers that this particular device should have a particular IP, which is pulled from the pool, as it is DHCP that is in use.

Strange then that my TP-Link router allowed reserved IPs from outside of the DHCP pool - perhaps they simply predicted that people might try to do so and adjusted their code to cope.

It seems that outside of network professionals, the terms “static IP” and “reserved IP” are somewhat - but incorrectly so - interchangeable. I think Static IPs are the old way of doing things that required too much work and had too many pitfalls, like needing manual configuration of each client device.

To anyone still wondering, Sonos speakers can’t be configured to take static IPs, but most routers can reserve IPs for devices and therefore Sonos devices can be given a reserved IP.

I thought otherwise; indeed the Apple utility insisted that this be done. It is like a town council handing out house numbers - the ones that are reserved should not be accessible to the pool from which unreserved ones are handed out their house number, else the reserved number may get handed out to a random house if the reserved house is offline, causing issues when latter turns up again asking for a house number. So I think at any rate.

But: When in the mood to suffer some consequence, I will expand the pool on my ISP router back to what it was, with reserved IPs then within that expanded pool and see what happens. It will be just one toggle to see the outcome.

Hi @Kumar

If you look at it from the client device’s side, it makes sense - when you use reserved IPs, the client device is still using DHCP, therefore it makes sense that the IP comes from the DHCP pool. When you set Static IPs, you turn off DHCP in the client’s settings - DHCP is not used and therefore neither should the pool be used.

On the router side, reserved IPs are reserved - they are only handed out to the associated MAC address and are not handed out to any others. Like booking a particular reserved table in a restaurant, if someone else shows up and asks for a table, they don’t get that one.

I guess you just have to meet the expectations of whoever wrote the code for each particular company/device.

Corry - that is exactly the reason why I explained in the OP the distinction between the two terms that I believe network professionals use. I have been involved in threads here before where the people contributing did not appear to understand the difference.

As stated above, my router can’t facilitate Reserved IP addresses outside the DHCP range - the User Interface provides the user with no way to configure them, because Sonos devices can do nothing other than make a request via DHCP.

Update but before that, all kits works fine through all this experimenting so there is that to also consider.

I had changed the pool to 51 - 254 and set out reserved addresses between 2-50. Devices with reserved addresses ended up with that address, or another in the pool beyond 51. 

I then reexpanded the pool back to 2 - 254, with no other changes made.

Now the same story except that all addresses are lower than 50, because there aren’t more devices.

I can also see that an address reserved for an item that has not been powered on has been given to another device that had no reservation. 

In both cases the majority of kit with reserved addresses get that address.

ISP router made by Dasan networks; google says Vietnamese.

This makes me nervous. I recommend powering down and rebooting everything if you change the DCHP pool. If the leases have all expired, been renewed, and the system is still stable, you can probably skip the mass reboot.

After toggling the DHCP pool back to its full size, I did the full reboot of everything process. As I had done when I had reduced it in size and done the IP reservations in the router. 

I could move the DHCP management to what seems to a more orthodox TP link router that, wired just downstream of the ISP router that is being eccentric, is a TP Link that is just now being used in access point mode, but I am not confident of other things I may have to change as well, to leave the ISP just as a feeder of internet to the TP Link that will then move to router mode.

So as long as things keep working, I have to leave them in the state they are!

But I think I will do another full reboot of all kit since that is just hardware powering on/off and see if things change.

Outcome - Nothing changes; most of the Sonos kit has the reserved addresses, but there are still a few that do not.

I reserve all regular network clients, SONOS or not.

All Sonos kit and associated devices like the NAS are reserved, but the router still seems to ignore some of these reservations, as it seems to do for the TP link devices with reserved addresses on the network. But everything seems to be hanging together and working fine, so I guess for now this is a problem that does not need a solution.

Some routers support a limited number of reservations. 

That does not look to be the cause of the eccentric behaviour here, I checked. But if it all hangs together, eccentricities are ok  I guess.