Joined two networks - a problem arose

[Arksun]

We joined two home networks each with their own gateway. Each device accessed the internet from their own gateway, but could communicate with other devices like a regular LAN.

Network A's router 192.168.1.1 was set to dish out IPs with DHCP to its intended devices, while network B's router 192.168.1.201 had it's DHCP disabled with all its devices' IPs configured with static IP's with gateways set to 192.168.1.201.

Everything was working fine, until Network A's internet connection died.

All devices on network B still connects to the internet, except for an Xbox One.

The Xbox one's IP is static on 192.168.1.204 with gateway on 192.168.1.201, but it can't connect to the internet.

Networks A and B are connected to each other with an Ethernet cable between the two routers. Disconnect that cable, and the Xbox one connects to the internet again. Connect the cable, and it loses connection. All other devices work as intended.

Any network guru's around that can shed some light?

 

[P00HB33R]

Try disabling UPNP on the XBOX and both routers.

 

[Gnome]

If what P00HB33R says doesn't work:

How is your DNS configured? Statically I assume also?

The following happens when you type a URL:
The device makes a DNS request (your DNS is static also I hope?). If that fails you already have a problem.

Next the DNS server responds with an IP. The network device now applies the Netmask. If your netmask is 255.255.255.0 then the IP range 192.168.1.1-254 is considered local.

If the IP is local the device sends out an ARP request for the mac address of the device owning the IP. If the ARP is answered the network packets are then sent.

More likely in your case (because it is the internet), the IP is not local (or you messed up your netmask).
If the IP is not local to the network, the packet is sent to the gateway which then follows the same process to send it to its own next hop on the network.

I would ensure that your Netmask, DNS and Gateway are all correctly set to static IPs.

 

[Nerfherder]

Feels like an IP conflict... I'm not sure how the xBox handles that.

 

[SauRoNZA]

The deeper question is why the need for this?

Two completely different ranges with their own DHCP servers and a Static Route to the other network is how it should rather be done.

And that’s only if there is really a need for this split at all.

 

[P00HB33R]

The deeper question is why the need for this?

Two completely different ranges with their own DHCP servers and a Static Route to the other network is how it should rather be done.

And that’s only if there is really a need for this split at all.

Totally agree, but I think its a bit "next level" for your average home user.

 

[EasyUp Web Hosting]

The deeper question is why the need for this?

Two completely different ranges with their own DHCP servers and a Static Route to the other network is how it should rather be done.

And that’s only if there is really a need for this split at all.

One can only assume it's because Network A uses it's own internet connection (ADSL) and Network B uses it's own internet connection (LTE).

Could have been done better, but that's what they have...

I agree with @Nerfherder, sounds like a IP conflict.

 

[Arksun]

The deeper question is why the need for this?

Two completely different ranges with their own DHCP servers and a Static Route to the other network is how it should rather be done.

And that’s only if there is really a need for this split at all.

It's two households that LAN games on PC together regularly and uses each others media and file servers. Each household uses their own internet to not eat each others cap.

Sorry for taking so long to respond, but I tried what was suggested by p00hb33r and after turning upnp off and forwarding the ports the old fashioned way, the problem went away.

Thanks guys, problem solved

 

[SauRoNZA]

It's two households that LAN games on PC together regularly and uses each others media and file servers. Each household uses their own internet to not eat each others cap.

Sorry for taking so long to respond, but I tried what was suggested by p00hb33r and after turning upnp off and forwarding the ports the old fashioned way, the problem went away.

Thanks guys, problem solved

When it breaks again the better option would be a Static Route to the other network (so that it basically doesn't push all traffic through gateway as it would by default, but that specific range over that Static Route instead.)

That will keep the two networks completely separate and self-managed while allowing traffic to each other.

It isn't always possible with all hardware combinations though, but you might be lucky.

Ultimately not having uPNP might run you into some issues. Port Forwards in most cases work for the average stuff but the more dynamic things can make ***.

 

[Gnome]

When it breaks again the better option would be a Static Route to the other network (so that it basically doesn't push all traffic through gateway as it would by default, but that specific range over that Static Route instead.)

Unless the static route is added to each device, it would still need to go through the gateway...

 

[SauRoNZA]

Unless the static route is added to each device, it would still need to go through the gateway...

Yeah that would be the idea.

But I guess technically either way it would still go “through the Gateway” just not go via the default route.

 

[P00HB33R]

It's two households that LAN games on PC together regularly and uses each others media and file servers. Each household uses their own internet to not eat each others cap.

Sorry for taking so long to respond, but I tried what was suggested by p00hb33r and after turning upnp off and forwarding the ports the old fashioned way, the problem went away.

Thanks guys, problem solved

Happy to hear you got it sorted. I would however suggest maybe buying a small Mikrotik RB750 and segment your network a bit better. I will create a script for your mikrotik if you have any troubles setting it up. In th elong run it would save you a lot of headaches, and as a added bonus you could go balls to the wall with some qeues, shaping, etc with the mikrotik.

 

[Arksun]

Yeah, I used to work a lot with those back in 2007 when I was still in IT, I should look into getting myself a board again