topic Re: DEFAULT GATEWAY IP in My Router

Default Gateway IP

myrddin55 — Mon, 03 Mar 2025 17:43:23 GMT

This morning I discovered that I couldnt connect to my NAS through my domain nor using the IP assigned to it on my network. Further investigation reveals that the default gateway has now changed and that a new IP has been assigned to the NAS, though the router is unable to connect to the NAS using it. The IP that was assigned (fixed) had a load of port forwarding rules associated with it, so the question is, why has the IP addresses been changed and how do I change the Default Gateway back to what it was?

Moderator's note by Mike (Mav): All caps title/text edited as per Forum rules.

Re: DEFAULT GATEWAY IP

Baldrick1 — Mon, 03 Mar 2025 14:29:31 GMT

Moderator's note:
Thread moved from My Router to My Account/Billing

Re: DEFAULT GATEWAY IP

Baldrick1 — Mon, 03 Mar 2025 21:19:59 GMT

@myrddin55

I have moved your topic because you have stated that you have paid for a fixed IP address.

Unless you have paid the fee then be aware that Plusnet no longer provide fixed addresses.

Edit

Topic moved back after further clarification.

Re: DEFAULT GATEWAY IP

RobPN — Mon, 03 Mar 2025 15:00:23 GMT

@Baldrick1

I'm confused ...

Re: DEFAULT GATEWAY IP

Dan_the_Van — Mon, 03 Mar 2025 15:18:26 GMT

@myrddin55

could you explain a bit more to which default gateway you are referring to, the NAS drive or the broadband gateway.

What has changed, example would be handy.

Are you using back to back routers, (double NAT)?

Edit: and what @outcast has posted

Re: DEFAULT GATEWAY IP

outcast — Mon, 03 Mar 2025 15:28:44 GMT

It would help if @myrddin55 could reword the issue, as the question doesn't make much sense,

and the use of "default gateway" terminology confuses thing more, as a changed gateway is probably irrelevant.

Typically the nearest thing to being a "default gateway" is the WAN side first hop Plusnet gateway device externally encountered by the home router (and can change).

The NAS device's network settings might have a manually assigned "default gateway" (sometimes called "default route") - which would be the static LAN IP address of the Plusnet Hub.

If there is a static WAN IP address, which shouldn't have changed, it is neither "default" or "gateway"

If this refers to a DHCP assigned LAN IP address (marked as fixed) for the NAS, but now changed, is not "default" or "gateway".

If the NAS had it's network settings manually set with static LAN values, and has now lost them, well good luck with that !

Re: DEFAULT GATEWAY IP

myrddin55 — Mon, 03 Mar 2025 17:13:43 GMT

Good evening Baldrick,

Kindly return my post back to whence it came. I am not accountable for nor responsible for Plusnet marketing strategies. I purchased the service last year, that you think I haven't paid for it is an affront.

Return it now please. Thank you

Re: DEFAULT GATEWAY IP

myrddin55 — Mon, 03 Mar 2025 17:39:01 GMT

Hi
Thank you you for your more tacful reply.

The attachments may help. Basically I can no longer connect to my NAS nor adjust the settings through the DSM (Disk Station Manager). Why I can no longer connect to it through the Hub2 Router is a mystery. I turned the router off last night accidently (I meant to switch of the phone charger) but decided to leave it off as I thought the rest would do it some good. In the morning when I switched it back on nothing worked include the net connection to the PC (ethernet) and the MESH (also ethernet). The same applied to the NAS which I connect to via an external domain. When I checked the admin centre on the router I noticed that key IP addresses had changed including the NAS and the default gateway (which is also the IP for the NAS). I have no idea why it changed as DHCP is inhibited.

Apologies if my first made no sense to you, I am a layman.

Regards

Myrddin55

Re: DEFAULT GATEWAY IP

myrddin55 — Mon, 03 Mar 2025 17:42:11 GMT

Images

Re: DEFAULT GATEWAY IP

myrddin55 — Mon, 03 Mar 2025 17:42:48 GMT

Images

Re: DEFAULT GATEWAY IP

outcast — Mon, 03 Mar 2025 17:59:57 GMT

@myrddin55

The "default gateway" is a valid Plusnet gateway device - so that isn't a problem.

Your broadband IP address IS a valid Plusnet STATIC IP address - so you haven't lost that.

The loss of Hub2 settings is something I don't know about and defer to @Dan_the_Van 's expertise.

Can you access the NAS's DSM using the "Private IP address" shown in Reply #9 when typed in to your browser's address bar ?

If this was mine, I'd be setting a static LAN addresses on your NAS and MESH - outside the router's DHCP address range.

Re: DEFAULT GATEWAY IP

myrddin55 — Mon, 03 Mar 2025 18:00:18 GMT

Your last suggestion is a good one, however doesn't the inhibiting of the DHCP effectively do the same this? As you can see from the image that the pervious IP to the NAS is associated with a lot of port forwarding rules. I'm trying to avoid re entering them all again if I were to press the factory reset button.

Re: DEFAULT GATEWAY IP

Dan_the_Van — Mon, 03 Mar 2025 18:09:37 GMT

@myrddin55

*** Before you do anything take a backup ***

Thanks for the reply and images.

You do indeed have a static IP address, regarding the broadband default gateway, this is very likely to change each time the Hub is rebooted, I would say your issue has nothing to do with it as the gateway is only referenced for outbound connections.

With regards to the NAS drive, referring to IPV4 table jpg file, the MAC address for the NAS has changed from

00:11:32:F9:D1:42 to 00:11:32:F9:D1:41 this has resulted in the NAS drive IP Address being assigned by DHCP so it is now 192.168.1.101.

The change of MAC address worries me as that should not happen

What you could do here is to change the port forward rules to use the device name rather than a IP Address, I think this way the rule should always work regardless of IP Address, there should be no need to delete the current rules just change to the Device Name.

Come back if you need to clarify anything

Re: DEFAULT GATEWAY IP

myrddin55 — Mon, 03 Mar 2025 18:12:29 GMT

As per my previous, this is most unhelpful. Move it back to the correct forum please. Thank you

Re: DEFAULT GATEWAY IP

myrddin55 — Mon, 03 Mar 2025 18:21:21 GMT

"What you could do here is to change the port forward rules to use the device name rather than a IP Address, I think this way the rule should always work regardless of IP Address, there should be no need to delete the current rules just change to the Device Name."

That's the problem, I can't get into the NAS settings because I cant connect to it. I think I may have to back up all the setting on the Hub 2 and either hit the Factort reset or buy a new router. If it's the latter, any recommendations? I rather like the look of the Synology Mesh Router MR2200ac

Re: DEFAULT GATEWAY IP

Dan_the_Van — Mon, 03 Mar 2025 18:24:17 GMT

@myrddin55

Did you try 192.168.1.101 as detailed in the IPV4 table?

Try connecting locally not via a cloud based app

Re: DEFAULT GATEWAY IP

outcast — Mon, 03 Mar 2025 19:07:24 GMT

@myrddin55

This might sound like a stupid question, but WHY are you using loads of port forwarding rules with a NAS ?

Inside your LAN you SHOULD be able to access it just using the NAS's network HOSTNAME or using a fully qualified domain name(s) - (for example 'nas.myrddin55.plus.com' or 'synology.myrddin55.plus.com'), or using it's LAN IP address.

To access your NAS remotely from elsewhere on the internet, you should be using the built-in VPN server 'package', and then ONLY forward the relevant VPN ports (e.g. UDP 1194 for OpenVPN, or UDP 500, 1701, 4500 for IPSec VPN).

Similarly there appears to be some sort of "Mobile application" which ONLY requires TCP ports 5000 and 5001 forwarded.

You should NEVER allow other port forwards from the WAN to LAN to access a NAS - you are inviting hackers to access your files - as they will have unlimited attempts at brute force attacking your login details !. Earlier today in an answer to somebody else, I checked MY home network firewall, and could see that hackers were port probing my connection at a rate of FIVE attacks per SECOND and my connection is invisible from the internet (so they don't know that anything is there), the rate of attack would be much higher if ANY of my network ports were visible because of unnecessary port forwards.

Re: DEFAULT GATEWAY IP

paul_blitz — Sat, 15 Mar 2025 16:49:15 GMT

For some reason, sounds like your original static IP mapping has gone wrong, due to the different MAC address. Thoughts:

- Does your NAS have *TWO* LAN ports? Maybe the cable is in the wrong port (would tie in with the MACs being 1 different) (which model is the NAS?)

- Using a local connection from a local PC, connect to the NAS - by cable, not using Wifi. Try the old IP, try the new IP (192.168.1.101). If you can't connect, forget the router, and go back to basics....

- Did the NAS have an IP address set ON THE NAS? Or was it set by a fixed DHCP address? (both are very valid ways to allocate a fixed IP to a device)

- connect a cat5 cable directly from your PC to the NAS. Power-cycle the NAS: if set to use DHCP, I'm hoping this might cause it to revert to it's default IP, which I believe is 192.168.1.1. Set your PC to have a static IP in the same range, eg 192.168.1.2. Try to connect to the NAS on .1, .101, and whatever its original IP was.

- what does the ethernet port LED (on NAS) show? What are the front panel LEDs doing?

And something very different: I just discovered there is a "DS Discovery" app for a phone / tablet: it will probe the local LAN to find a NAS, then let you connect to it. If it works, then if nothing else, it will show you the IP address! See this YT video: https://www.youtube.com/watch?v=VStRCQMnudI

If you are worried about the effect of power-cycling your NAS (I'm assuming from comments that it's a Synology unit) without doing a nice software driven shutdown, don't panic. Our organisation has three Synology, and over the last 5 to 10 years that have all had unplanned power-downs (and I'm meaning 'loss of mains', rather than using front panel) and have never suffered any problems.. To shut down a Synology from the front panel, you need to press and hold the power button, for 3, 10 or 30 seconds (depends on which web page you read!)... in any case, you'll get a beep when it's accepted the button press.