One modem, two router, two networks - going crazy to figure it out

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alexT
Posts: 39
Joined: Thu Sep 10, 2020 5:15 pm

One modem, two router, two networks - going crazy to figure it out

Post by alexT »

Hello, I am a newbie who thought networking is easy. Wrong! going a little crazy after trying to setup two networks, using one modem and two Linksys 1900ac modems, connected to each other via ethernet, both running Gargoyle 1.12.0.

This is my attempt to start fresh by hopefully get someone to HOLD MY HAND and tell me which settings to change.

Goal is to have two separate networks. Sharing a single internet connection.

Router #1 is connected to a ARRIS CM8200 DOCSIS 3.1 Gig Modem. It works fine. By fine, I mean devices can connect to it and connect to the internet without any issues. Here is the status page scrnshot: https://nimb.ws/SAltMU
Connection > Basic scrnshot: https://nimb.ws/KDbACt

Router #2's WAN port is connected to one of Router #1's LAN port.

I don't want Router #2 to be connected to Router #1 wirelessly. They are in separate buildings. Distance too far. Using ethernet buried underground.

Now, could you please tell me what the settings of Router #2 should be? I've read and read but I've gotten more confused over time. For example, can you start by telling me if CONFIGURE DEVICE AS be set to Wireless Bridge/Repeater?

I know it is probably really boring to talk baby to someone who seems like an idiot. But it can also help you see Gargoyle from the eyes of a newcomer who is overwhelmed by all the settings. He reads the documentation but still can't figure it out. How could that be? Because terminology has a way of meaning multiple things to people thinking outside the required context.

if you're wondering, I ended up with Gargoyle because at one point thought frequent disconnections was due to Linksys firmware. But after I flashed both modems, I realized there a bunch of new settings I don't understand.

Lantis
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Joined: Mon Jan 05, 2015 5:33 am
Location: Australia

Re: One modem, two router, two networks - going crazy to figure it out

Post by Lantis »

If you want them to be separate networks, router #2 needs to be set to
Gateway
Connect via: DHCP Wired
LAN needs to be any subnet that isn't already taken by your modem and router #1 (192.168.2.1 looks ok?)
If you don't want LAN#2 to access resources from LAN#1, you'll need to do some additional firewall rules.

If you want them to be one big network, change from WAN to LAN on router#2.
Gateway
Connect via: disabled
Disable DHCP
http://lantisproject.com/downloads/gargoyle_ispyisail.php for the latest releases
Please be respectful when posting. I do this in my free time on a volunteer basis.

alexT
Posts: 39
Joined: Thu Sep 10, 2020 5:15 pm

Re: One modem, two router, two networks - going crazy to figure it out

Post by alexT »

Hello, thanks so much for your response.
LAN needs to be any subnet that isn't already taken by your modem and router #1
By subnet, you mean "Subnet mask"?

Does the subnet modem and Router 1 have to be different from each other? If so, how do I determine the subnet of the modem?

It is set to 255.255.255.0 on both Routers. So what should I set the subnet in Router #2 to make it different? The address of Router #2 is set to 192.168.2.1

Lantis
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Joined: Mon Jan 05, 2015 5:33 am
Location: Australia

Re: One modem, two router, two networks - going crazy to figure it out

Post by Lantis »

Without going into too much detail (you can read more if you're interested), a subnet is just a group of addresses.
There's a few different notations for them, Gargoyle is using the first address and the subnet mask.
A subnet mask "locks" the bits of the address range. 255.255.255.0 implies that only the last octet can move. So 192.168.2.1/255.255.255.0 implies 192.168.2.1-192.168.2.255.

If your first router is using 192.168.1.1/255.255.255.0, then using 192.168.2.1/255.255.255.0 is fine and I wouldn't complicate it any further.

Yes router 1 (and router 2) must be different to the modem.
It might be difficult to find out the modems subnet if it only exposes your proper WAN address to you. You'll know if you're having a clash because your network will fail due to routing issues.
http://lantisproject.com/downloads/gargoyle_ispyisail.php for the latest releases
Please be respectful when posting. I do this in my free time on a volunteer basis.

alexT
Posts: 39
Joined: Thu Sep 10, 2020 5:15 pm

Re: One modem, two router, two networks - going crazy to figure it out

Post by alexT »

Code: Select all

It might be difficult to find out the modems subnet if it only exposes your proper WAN address to you. You'll know if you're having a clash because your network will fail due to routing issues.
Perhaps this issue has been what has been causing the issues. With my previous setup, Router #2 had Internet access for a couple of days and suddenly there was no Internet. But Router #1 Internet access never stopped. But if modem subnet's mask was the issue, wouldn't both router's fail?

So can I find the subnet of my modem by calling my ISP's tech support?

alexT
Posts: 39
Joined: Thu Sep 10, 2020 5:15 pm

Re: One modem, two router, two networks - going crazy to figure it out

Post by alexT »

Hi Lantis, per your instructions, I set Router #2 on DHCP Wired.
The ethernet going into its WAN port has Internet access. But the router does not.

Here's my Basic Connection page: https://nimb.ws/gtO3IF
Here's the status page: https://nimb.ws/YkxzBG

There is no CURRENT IP in Intenet/WAN section. That should have an IP, correct? Any tips I would really appreciate.

Lantis
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Joined: Mon Jan 05, 2015 5:33 am
Location: Australia

Re: One modem, two router, two networks - going crazy to figure it out

Post by Lantis »

Yes. Have you tried rebooting both devices?
A log from router 1 might reveal if it is refusing to give it an address for some reason.
http://lantisproject.com/downloads/gargoyle_ispyisail.php for the latest releases
Please be respectful when posting. I do this in my free time on a volunteer basis.

alexT
Posts: 39
Joined: Thu Sep 10, 2020 5:15 pm

Re: One modem, two router, two networks - going crazy to figure it out

Post by alexT »

Hi, rebooting both devices didn't fix it. Router #2 still has no Internet access.
A log from router 1 might reveal if it is refusing to give it an address for some reason.
I figured out SSH access. But haven't been able to find a tutorial on Gargoyle site on how to output a log.
What command shoudl I use?

alexT
Posts: 39
Joined: Thu Sep 10, 2020 5:15 pm

Re: One modem, two router, two networks - going crazy to figure it out

Post by alexT »

I used command logread. Is this log you mean?

https://pastebin.com/81iNxMKx

alexT
Posts: 39
Joined: Thu Sep 10, 2020 5:15 pm

Re: One modem, two router, two networks - going crazy to figure it out

Post by alexT »

By the way, CONNECTION > ROUTING gives
subnet mask of 255.255.248.0 in front of my modem's IP. Could that be my modem's subnet? Screenshot: https://nimb.ws/pqL9Nd

Image

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