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My connection is now on fiber and since that was realized, all my IP addresses shifted from 192.168.1.xxx to 192.168.2.xxx.

I have tried to revert them back to 192.168.1.xxx, but without luck. Now for most part this is not a problem. I just had to configure a lot of stuff with the new address and that seems to work just fine now. But I do have a problem with reaching my VSeven MPEG24 switch which has a default address of 192.168.1.1 which is in another subnet. I have no clue how to solve that. I've tried hard resetting the switch, but I can't connect to it anymore.

Peter Mortensen
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Paul Sinnema
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  • Apparently your ISB modem/router gives out DHCP to your devices, and that subnet changed when your service changed. Set your devices up to the new subnet. – John Jul 25 '21 at 12:19
  • Does https://superuser.com/questions/1657740/2-routers-ip-range-changed-on-main-one-unable-to-access-2nd-one-anymore/ answer the question? – u1686_grawity Jul 25 '21 at 12:24
  • Would not this fit better at [Network Engineering SE](https://networkengineering.stackexchange.com/) ? – Veverke Jul 26 '21 at 20:06
  • Once you gain connection again, you should be able to enter the router configuration and choose whatever DHCP pool range you want (aka, your previous one). If you neeed some machines with a fixed IP, you still can do it with DHCP, you only have to configure the DHCP service to give IP adress X to the machine with the MAC Y. – bradbury9 Jul 27 '21 at 06:27

1 Answers1

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Temporarily change one of your computers' IP address to be in the 192.168.1.0/24 range and you should be able to connect to your switch (you will be disconnected from the Internet). Then just configure your switch's IP to be in the 192.168.2.0/24 network and switch back your computer's IP address to whatever it was.

Dan
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    And, better yet, if OP doesn't understand what DHCP is or how it works, or how networking and subnets work, then it's sensible advice to **stop using manually configured IP addresses** altogether. – J... Jul 26 '21 at 12:53
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    I know what DHCP is and how it works. But that knowledge doesn't explain why the addresses changed after going to a Fiber connection. I can't stop using configured IP addresses because some applications in my home expect the IP address to be fixed. – Paul Sinnema Jul 26 '21 at 13:10
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    @PaulSinnema Then you can't have some upstream service provider controlling what subnet you are on. – Kaz Jul 26 '21 at 13:49
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    @PaulSinnema DHCP runs on your integrated fiber/cable/dsl router. When you change your primary router, the DHCP server goes with it and you get whatever default subnet it's configured with out of the box. If you need internal static IPs then you need to understand DHCP and take control of it, either by shifting that responsibility away from your ISPs provided combo/router device to something else on your network that can provide DHCP services, or by actively configuring DHCP on that provided device to suit the needs of your internal network. – J... Jul 26 '21 at 16:43
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    @PaulSinnema "I know what DHCP is and how it works", ok fine. "But that knowledge doesn't explain why the addresses changed after going to a Fiber connection", ah, it seems you were mistaken. – PcMan Jul 26 '21 at 17:46
  • Strictly speaking in terms of the OSI model, applications should not rely on fixed ip addresses but on names and DNS. So perhaps you might find it possible after all to adjust your relevant applications – Hagen von Eitzen Jul 26 '21 at 20:25
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    The reason for the change is probably that the new fiber modem uses 192.168.1.0 itself. You happen to have a switch that is intelligent enough to detect that and pick the next subnet for the LAN side. Otherwise you wouldn't have been able to connect to the Internet. – Jeffrey Jul 26 '21 at 21:32
  • Well the first thing I'd do is find out what device is providing the new addressing and then log into it and correct it. You may have to look at -why- it is doing that and correct that issue as well. ...Is this some device that you don't administer? Then you aren't in control of your own network. Put a router in between you and them and don't give them the password. Now you control your network. Log into your DHCP server and set it up the way you want it setup. The real question here is "who is in control of your network?". – Larryc Jul 27 '21 at 00:51
  • My DHCP server runs on my Synology NAS not the Router. But after changing from copper to fiber the default Gateway also changed to 192.168.2.xxx. But this is no long an issue. The answer provided gave me the ability to change the IP on the switch and everything is working like a charm again. And yes I do need a few fixed IP addresses. F.i. my Loxone system expects the external IP addres to be forwarded to the Miniserver. Because of that I need it at a fixed IP address (or do I?). I'm fixating it using the Miniservers MAC address. – Paul Sinnema Jul 27 '21 at 17:20
  • @PaulSinnema Probably because your fiber modem **also** had a DHCP server, enabled by default out of the box, and was competing with the DHCP server on your NAS. The solution there is just to *turn off the DHCP server* running on the fiber modem/router. – J... Jul 29 '21 at 18:40
  • No, I disabled the DHCP server in the ISP Modem. Ah, but wait a moment. There is a second modem attached. That might be the cause. A little black box, where the Fiber comes in, is attached to the Experiabox V10 of KPN. It is connected to the WAN port. Hmmm, then it should not have any influence should it? Maybe I should ask this question on the ISP's Forum. – Paul Sinnema Jul 30 '21 at 23:47