Two Routers, One Cable Modem

[TwiceHorn 31554]

Is it possible to connect two wifi routers to one cable modem?  We have a relative staying temporarily, and he's a big gamer and streamer.  Rather than configure his router as a bridge or repeater, we are considering just setting it up with it's own SSID and NAT configuration for gaming.

From what I can recall, Spectrum required the MAC number of the cable modem I have and it serves out an IP address to it.

The current network is configured like this:  coax to cable modem, ethernet out to wired house.  The existing wifi router then is connected to a Cat 5 wall port and various things connected by wifi and ethernet to that router.

He's trying to use a Cat 5 wall port upstairs, which should be WAN to the cable modem, but so far it's not working.  We did hook his router direct to the cable modem, with the existing router thus offline and it connected up fine, but then he took it upstairs (and I reconnected the downstairs router) and no go.

TIA.

[crash_davis 23115]

this may help.

https://hetmanrecovery.com/recovery_news/connection-of-2-routers-in-one-network-wifi-gain-shared-resources.htm

[Nice Guy Eddie 13528]

49 minutes ago, TwiceHorn said:

Is it possible to connect two wifi routers to one cable modem?  We have a relative staying temporarily, and he's a big gamer and streamer.  Rather than configure his router as a bridge or repeater, we are considering just setting it up with it's own SSID and NAT configuration for gaming.

From what I can recall, Spectrum required the MAC number of the cable modem I have and it serves out an IP address to it.

The current network is configured like this:  coax to cable modem, ethernet out to wired house.  The existing wifi router then is connected to a Cat 5 wall port and various things connected by wifi and ethernet to that router.

He's trying to use a Cat 5 wall port upstairs, which should be WAN to the cable modem, but so far it's not working.  We did hook his router direct to the cable modem, with the existing router thus offline and it connected up fine, but then he took it upstairs (and I reconnected the downstairs router) and no go.

TIA.

I thought you could hardwire one wifi router into another one like you describe above. I would check to see if that Cat 5 wall port works by plugging a device (non-router) into it.

Is he attempting to run a VPN from his router or desktop? If you're also doing that, I've heard stories of limitations of using 1 VPN on a single data line. I'm unsure if the main router or data line is the culprit.

[blacklab 11955]

that's not going to work

the cable modem ethernet out just has one out, it's not a router that can handle multiple things hooked to it.

You could plug in your router strait to the modem, then have one of the outs of it go to the cat5 wall.

Then he should be able to plug his router into the wall and change the settings on it so it's looking for dhcp instead of a modem.

[elfenix 34338]

a router plugged into another router just creates a subnet.  it'll still go through your router's rules.  either plop his router where yours is and connect through his SSID, or configure yours for gaming/whatnot. 

[MonkeyDoughnut 10357]

13 minutes ago, elfenix said:

a router plugged into another router just creates a subnet.  it'll still go through your router's rules.  either plop his router where yours is and connect through his SSID, or configure yours for gaming/whatnot. 

Pretty much this. If he needs NAT, his router will need to be connected direct to the cable modem/router and yours behind it or add his NAT configs to your router for time being (easiest way)

[TXSG8R 3362]

With gaming he will likely run into issues due to being double NAT anyway.  Everything on your side of the modem is a private subnet.  When you hook his router up he is going to get a private subnet hooked to a private subnet, which furks up return traffic.  

Why would the network connection upstairs go to the wan side of your router?  That should be the modem.  All your house ports should go to a switch/LAN side of your router.     

[idigTexas 2290]

Does he actually need NAT, or just an internet connection?  Unless he is hosting a gaming server, he should only need a connection, in which case, there is nothing to be gained my segregating his activities unless you want him behind his own router for your protection.  Multiple wifi setups may interfere with each other if they are close enough, but it isn't clear that this is what you are trying to do.

It sounds like to me that you just have a bad wall jack.  If his computer works when connected to his router when the router is connected directly to the modem, then it should work when connected via the wall jack.  Is he connecting to his router via CAT5 or wifi?  If he is connecting via wifi, then leave your router off and see if he can connect, if he can, then you have wifi interference.  Can anything connect via the wall jack? 

[TwiceHorn 31554]

6 hours ago, TXSG8R said:

With gaming he will likely run into issues due to being double NAT anyway.  Everything on your side of the modem is a private subnet.  When you hook his router up he is going to get a private subnet hooked to a private subnet, which furks up return traffic.  

Why would the network connection upstairs go to the wan side of your router?  That should be the modem.  All your house ports should go to a switch/LAN side of your router.     

RIght, I get that the NAT will have to be on one router only if one of them is used as a repeater or bridge.

Blacklab answered the fundamental question.

Originally, the cable modem and router were set up in the northeast corner of the house, where there is a study.  The study is underused.  But I left the cable modem there, plugged it into the house network, and put the router in a more central room that gives better coverage.  So the house network was WAN, which didn't matter because no one uses the ethernet jacks.

He was thinking he wanted a super-strong/fast connection with his own router, with ports opened for his gaming, etc.  In other words, he just wanted to be able to use his own router with its own configuration.  I thought if the cable modem would serve his router, that would be effective for his purposes.

I put it in the original configuration, modem to router to house network and now it works, but the signal is a little more attenuated in other parts of the house, which doesn't really matter.  I need to get a stronger router anyway.  I'll probably have to open a couple of ports for him on mine.

Edited March 30, 2021 by TwiceHorn

[TXSG8R 3362]

Don't get a stronger router.  Get a mesh/distributed system, preferably with a wired backhaul between the APs and gateway (or primary and extenders).  You want as much stuff on the 5Ghz spectrum (more/protected channels so you can reduce/eliminate, faster speeds since the 2.4Ghz spectrum maxes out at 150Mbps), which doesn't propagate as well through obstacles or carry as far.  You're better off having multiple access points that are closer to each device.  The general rule of thumb is one wall away.  

[TwiceHorn 31554]

1 hour ago, TXSG8R said:

Don't get a stronger router.  Get a mesh/distributed system, preferably with a wired backhaul between the APs and gateway (or primary and extenders).  You want as much stuff on the 5Ghz spectrum (more/protected channels so you can reduce/eliminate, faster speeds since the 2.4Ghz spectrum maxes out at 150Mbps), which doesn't propagate as well through obstacles or carry as far.  You're better off having multiple access points that are closer to each device.  The general rule of thumb is one wall away.  

Yes that's what I meant. But thanks for the tip. 

[elfenix 34338]

5GHz is for plebs, 6GHz is the new hotness.

[TwiceHorn 31554]

11 minutes ago, elfenix said:

5GHz is for plebs, 6GHz is the new hotness.

What about my chip? Did gates rip me off? 

[elfenix 34338]

14 minutes ago, TwiceHorn said:

What about my chip? Did gates rip me off? 

you need one of the mrna vax and the johnson vax. 

Edited March 30, 2021 by elfenix

[Celery Man 21003]

which network is for the scat porn

[TwiceHorn 31554]

On 3/30/2021 at 1:21 PM, TXSG8R said:

Don't get a stronger router.  Get a mesh/distributed system, preferably with a wired backhaul between the APs and gateway (or primary and extenders).  You want as much stuff on the 5Ghz spectrum (more/protected channels so you can reduce/eliminate, faster speeds since the 2.4Ghz spectrum maxes out at 150Mbps), which doesn't propagate as well through obstacles or carry as far.  You're better off having multiple access points that are closer to each device.  The general rule of thumb is one wall away.  

Welp, I followed your advice, actually had pulled the trigger before seeing this post and got the cheap Orbi, with two bands and two satellites.  I get that mesh emphasizes coverage over speed/throughput, it works pretty well and gives me 60-70% rated speed.  

Our temporary resident plugged his router into the routed wall jack and it seems to be working fine for his purposes upstairs, DHCP'ing a different network range.

I initially spread the satellites probably too far apart (says 30 feet) and it worked, but tended to use 2.4Ghz for the backhaul, which slowed speed down.  I followed your rule of one wall and have pretty good coverage through the first floor.  Mesh is kind of deceptive that way, because the satellites will connect to a device by 5Ghz, but if the backhaul is on the 2.4, you're getting 2.4 speeds on a 5 connection.

Having jacked with it for a day or two, I take your point about wired backhaul for speed, but this seems to suit our purposes pretty well, giving good coverage and connections and pretty good speed.  I don't see a need now to look at the more expensive options.

With just two satellites and following your rule of one wall between each node for best results, I'm skeptical of the claim that this could cover 4500 sq feet, which I think is the claim, it may be 3000, but that's a bit of a stretch also. It may cover, as far as connecting devices, but the speed is going to be limited.

[TXSG8R 3362]

Yea, that coverage area will be 2.4Ghz, not 5.  It will also be the bleeding edge of usable signal, marketing gonna market. Just like the advertised speed will be 1 device like a foot away from the wired AP. None of their shit reflects real world usage. Wireless mesh is great if you don’t have the option to wire your backhaul, but it’s always going to suffer from physics. I haven’t messed with orbi before, we tend to push TPlink Deco, but usually you can add some more APs to increase your coverage if you still have some weak spots.