Adding a new 3rd party Router behind the Sagemcom 5464

[Billx]

To @KeithFrench 

Previously in another thread, Keith, you responded:

on ‎10-05-2024 10:05 PM

Hi @Billx 

I don't want to dwell on this, as it is not your thread. However, a daisy chain network - that is not a term used in 802.11, one router is an extender from the other. As to your other question, this all depends on how you connect your 3rd party router & the way that you configure it. To use the same subnet as the Sagemcom, you would need to put the other router into bridge mode (it is then just an AP, no routing at all), give it an IP address on the 192.168.1.0 network and connect the Sagemcom to one of its LAN networks. You will also need to disable one of the DHCP servers. Clients connected to either router have full connectivity between them

Connecting the Sagemcom to the WAN port of the other router means that you should not enable bridge mode at all but that the 3rd party one must be on a different network (e.g. 192.168.2.0). This time clients connected to the 3rd party router can connect to the ones on the Sagemcom, but you may need port forwarding to configured for the Sagemcom clients to access servers on the 3rd party one.

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And then I responded:

‎11-05-2024 02:36 PM

Thanks very much, @KeithFrench 

I am currently looking only at the option of using the same subnet.  I have also read a bit more about this at another website.

I would intend to disable the wireless portion of  the Sagemcom. Going via this route, would the remaining ethernet ports on the Sagemcom AND the new 3rd party router be available as normal?

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(EDIT 3:25 PM : You also mention that ' you would need to put the other router into bridge mode'

I assume you mean the 3rd party router. I understand that some routers only have one mode e.g. the Sagemcom itself. You can't select a mode in Sagemcom, only configure it in other ways.)

Thanks

Bill

[Debbie-TalkTalk]

Thanks for your help @KeithFrench 

Hi Billx

Do you need help with this?

Are you experiencing any issues with your connection/router (at the moment)

[KeithFrench]

Hi @Billx 

I have explained in most of my replies to this thread, exactly what bridge mode is. My purpose on this forum is not to teach you everything to do with IP networking, but to help you with any problems. As yet you do not have any current problems, so please can we stop this now?

When or if you buy a 3rd party router, and if you have any problems, then create a new thread for that.

[Billx]

Hi @KeithFrench 

You made a big assumption Keith.

I NEVER said I will set the second router to bridge mode, because as I think you've gathered, I don't understand yet, what 'bridge mode' is. It seems 'bridge mode' means anything to anyone.

On the other hand, your last paragraph seems to be perfect:

Both routers need to be on the same subnet (or IP network), so set the Sagemcom to 192.168.1.1 and the other router to 192.168.1.2, both using a subnet mask of 255.255.255.0. Have only one DHCP server enabled & its IP address range going from 192.168.1.3 (assuming you do not need any other static IP addresses), up to 192.168.1.254

I suppose it would not matter which DHCP server was disabled.

(EDIT Monday 12:30 AM : If 'bridge mode' is as you say, and it cancels all the routing, why would anyone use such a stupid function? One might as well not have a router in the first place.)

Thanks very much

Bill

[Billx]

The following article is from 'https://us.hitrontech.com/learn/do-you-need-a-modem-with-an-ont/',

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Is an ONT a modem?

Technically speaking, an Optical Network Terminal (ONT) is not a modem. However, for fiber-optic Internet, an ONT acts similar to a modem because it communicates with an Internet service provider (ISP). There are three different types of modems: telephone (dial-up) modems, DSL modems, and cable modems. An ONT is not one of them.

Simply put:

• A modem (Modulator/Demodulator) converts digital signals to analog and vice versa.
• An optical network terminal (ONT) is like a modem, but for fiber-optic networks.

With an ONT you do not need a separate modem to communicate with your ISP. In fact, it wouldn’t work. Like a modem, the ONT communicates directly with the ISP, but unlike a modem, it communicates through infrared light pulses and fiber-optic wiring to get an Internet connection. With the fiber router connected to your ONT you can get access to Wi-Fi.

Because fiber technology works with light pulses, a standard modem won’t work. A modem is designed to convert an analog radio frequency (RF) signal sent over a cable into a digital signal (represented by 0’s and 1’s) so that any digital device can understand the signal. 

Fiber technology works differently by using one fiber-optic cable to send multiple signals at once via light pulses. So, instead of plugging a device straight into a modem for a solid wired connection on your fiber network, you can plug your computer directly into an ONT.

The purpose of the ONT is to act as the “last stop” in the telecommunication train between your local network and your ISP bringing you the Internet connection you want.

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As is clear from the article, an ONT is like a modem and acts exactly like a modem in the past would, in previous technologies. Adding a modem to an ONT, would result in 'no connection'. Therefore, current routers do not contain a modem. A current router is just a router, without a modem. Therefore, the article that I refer to above at 'EDIT Sunday 8:10 PM Here's Google's advice' would now turn out to be utter nonsense.

Bill

[KeithFrench]

There is a lot of confusion over bridge mode, but I am 100% correct, if you could enable that on your Sagemcom, directly connected to the fibre, you can kiss goodbye to any internet access. That is because as I keep telling you it turns off all routing functions, making it impossible to route IP packets between the private IP network that your devices use and the public IP network used on the WAN side of the router.

You have already told me that you will be setting the extra router in bridge mode (if it supports it), so double NAT is irrelevant. I have no intention of keep repeating myself.

I do not have the time to explain subnetting to you, it is a very complex subject & if you have no knowledge of the OSI 7 layer model, where switching occurs at layer 2 & routing at layer 3, that would need to be fully understood first. I have spent many years teaching all of this and it can take up to a day to complete. However, it can often leave some students totally confused.

All you need to know is that both routers need to be on the same subnet (or IP network), so set the Sagemcom to 192.168.1.1 and the other router to 192.168.1.2, both using a subnet mask of 255.255.255.0. Have only one DHCP server enabled & its IP address range going from 192.168.1.3 (assuming you do not need any other static IP addresses), up to 192.168.1.254.

[Billx]

This sounds all a jumble to me @KeithFrench . You're telling me about layer two and layer three. I don't know anything about layers.

Please tell me about subnets. Please tell me what subnet/subnets I would need to set up, and where each of the 2 routers need to be placed within the subnet/subnets. Is 1 subnet sufficient, or are 2 subnets necessary? Is this a DOUBLE NAT problem? Or isn't there such a thing?

EDIT Sunday 8:10 PM Here's Google's advice,

'If you have two separate ISP devices, a modem and router, turn off and unplug the ISP-provided router, then connect your modem directly to your Google Wifi device.

If your ISP-provided router is combined with the ISP's modem in a single device, enable Bridge mode on your modem/router combo to fix the double NAT issue. When you enable Bridge mode on your ISP router, it'll turn off its NAT and allow your Google Wifi device to be the sole device that performs NAT.

1. Connect a computer directly to your ISP-provided router with an Ethernet cable.
2. Log in to your modem and router combo, then find its settings to enable Bridge mode.'

So, Google thinks Bridge mode enabling, that is Modem-only enabling and disabling of the ISP router is necessary, to allow smooth non-Double NAT. Obviously it assumes that the ISP-provided router has 'Bridge mode enabling' setting within it. Note there is no mention of  'Bridge mode' within the new Google router/device. Google also implies that everything will work nicely, with just the modem part of the ISP router!

Bill

[KeithFrench]

Hi @Billx 

All local devices are on the same IP network, therefore all inter-device traffic is switched at layer two, not routed at layer three.

Yes, you are wrong Bill on the second point. If you could, which you can't, set the Sagemcom into bridge mode, it would disable all routing functions. Therefore, no traffic from the local network destined for the internet would ever work. They are on different IP networks and this traffic is routed between the two IP networks, hence you need a router for that.

"Bridge mode is a special router mode that disables the router functionality so you can use your ISP's combination router-modem unit solely as a modem paired with your own router." Here they are talking about the combined modem router as a router & the second router in bridge mode, which is exactly what we have been discussing.

[Billx]

@KeithFrench 

That doesn't fully make sense to me. You say that it is preferable if the third party router has 'Bridge mode' and that setting the new router to 'Bridge mode' would mean that 'all routing functions are turned off'. In that case, if 'all routing functions are turned off', how will a local device communicate with another local device, without there being routing?

Please Keith, I really don't understand the principle.

EDIT Saturday 5:14 PM : According to the article you referred, it says

'Bridge mode is a special router mode that disables the router functionality so you can use your ISP's combination router-modem unit solely as a modem paired with your own router.'

Therefore the 'Bridge mode' function should be on the Sagemcom, not the 3rd party router. Am I wrong?

Bill

[KeithFrench]

Hi @Billx 

From a very quick Google search:-

https://www.howtogeek.com/867942/what-is-router-bridge-mode/ 

[KeithFrench]

Bridge mode @Billx means that all routing functions are turned off and it becomes a layer 2 device, which back in the day is exactly what a bridge was (although WiFi was not around then).

You asked:-

So, you are confirming that the devices on the LAN ports & WLAN on the 3rd party router would have full connectivity with each other and the internet, simply via the ONE ethernet cable to the front router, the Sagemcom, using the same subnet for both routers?? 

Yes.

As to whether it actually will work without bridge mode - I can only theorise at this point, without router "x" in front of me, I have no way of knowing for sure. Your money, your gamble.

[Billx]

Well, that's all positive, @KeithFrench .That's a lot more than I expected.

In fact my intention is to use only the LAN ports & WLAN on the 3rd party router, and ignore everything else on the Sagemcom, apart from the single ethernet port on it connecting to the 3rd party router.

So, you are confirming that the devices on the LAN ports & WLAN on the 3rd party router would have full connectivity with each other and the internet, simply via the ONE ethernet cable to the front router, the Sagemcom, using the same subnet for both routers??

(As regards, whether the 3rd party router would have 'bridge mode', I don't know, it's only in my mind still. I don't even know yet what 'bridge mode' is. But you did say that it should still work, without having 'bridge mode')

Thanks

Bill

[KeithFrench]

Hi @Billx 

Thanks for creating your own thread. First off the desired 3rd party router, does it support bridge mode? It is probably not the end of the world if not, it should still work, but I wouldn't pay money for it if I wasn't sure.

Certainly yes, where the Sagemcom is concerned all four ports will still work (although one will be taken up with an Ethernet connection to one of the LAN ports on the other router). I can't see any reason why the LAN ports & WLAN on the 3rd party router would not have full connectivity with the Sagemcom Ethernet ports. However, as it is a 3rd party one, I cannot guarantee anything, that is where you will have to check.

You will need to disable one of the DHCP servers, the Sagemcom certainly allows for this, so even if the other router won't allow it, you could disable it on the Sagemcom.