Save me (can’t access the internet with more than 3 LAN wired devices connected to an 8-port switch)

[Ombre Jaune]

Problem: I can’t access the internet with more than 3 LAN wired devices connected to an 8-port switch (ie, the fourth device never works (and the fifth too of course), no matter the device).

Description of Problem: Our house has eight separate LAN outlets throughout the house for various devices (see below for details). I don't actually use all 8 and only have use for 4 or 5 devices at a maximum. The first three devices connected to the 8-port switch (see below for the two models when the issue is happening) work correctly, obtain an IP address, and can access the Internet. When a fourth device is connected, invariably, it can not access the Internet (they appear to receive an IP address but no Internet). To be clear, changing the order in which the devices are plugged into the switch, the fourth can never access the Internet. This includes when only plugging the TVs and Xbox (no WiFi router connected to the switch). I originally thought the issue was with the Linksys switch so I purchase a TP-Link switch (see equipment list below) – yet the issue is still happening with either switch so I assume both brands and different models can't exhibit the exact same problem (unless I'm missing something).

Provider: Time Warner Cable (Columbus, OH) – now called Spectrum.

Set-up / Equipment: Ubee MTA TWC Model DVW32CB LAN to my own Arris cable modem model SB6190 into a TP-Link TL-SG1008D 8-Port Unmanaged Gigabit Network Switch (the problem also happens when using a Linksys 8-Port Metallic Gigabit Switch SE3008)

Devices connected to the switch via LAN: Linksys WRT3200ACM router, ASUS RT-N56U router, Apple Extreme Second-Generation router, Samsung SmartHub, Xbox One S, Xbox One, Samsung TVs.

Process of elimination:

Each cable works individually when tested in the same port and the same device – most likely not the cables.

Each port works individually when tested with the same cable and the same device – most likely not the ports.

Each device works individually when tested with the same cable and the same port – most likely not the devices.

Each device works individually when tested with the same cable and the same port on both 8-port switches (see Set-up / Equipment above for models) – most likely not the switches.

I can’t figure out the issue.

I’m happy to provide any additional information required to diagnose the issue, solve the problem, and return to sanity.

 

[mxnerd]

Why do you need one modem, one modem gateway (which is also a wireless router), and 3 extra wireless routers?

All you need is one modem gateway DVW32CB which connect to your ISP Spectrum, and one ethernet switch, unless you have a big house and you put all 3 extra router into AP mode.

AP mode means you disable wireless router's routing function and the router become an ethernet switch + access point, then uplink it to main router using a LAN (not WAN ) port. These AP mode routers also shouldn't serve as DHCP servers and hand out IP addresses.

 

[Ombre Jaune]

The Uber does have the modem functionality but TWC charges about $10 per month to turn it. As such, I purchased the Arris and TWC has turned off the modem feature.

Yes, it is a large house and placing the wireless router in the basement doesn’t give me much coverage because of the thick floor containing large metal support beams and the fact that it’s not at the center of the house but at the very end.

The wireless routers are upstairs, one on each floor. The kids’ router is physically on only during limited hours (yes, I could do times access).

Any idea as to why I can’t get past 3 devices?

 

[mxnerd]

Any idea as to why I can’t get past 3 devices?

no. Probably the main router DVW32CB's DHCP IP range is too small and only hands out a few IP addresses?

Does the setup work before? How are all devices connected with each other? A simple diagram is better than nothing.

Did you put routers in each level into AP mode and uplink them using LAN port, and turn off DHCP service?

And what does each device's internal IP looks like?

 

[mxnerd]

Err. Since you said TWC turn off DVW32CB's modem and you uplink one of it's LAN port to modem, it becomes a switch+ access point. So which one is doing the routing function now?

 

[VirtualLarry]

It sounds to me like he's effectively got cable modem -> switch -> multiple routers / APs and devices. Need to fix topology of LAN, IMHO.

 

[ch33zw1z]

Network is being over complicated. One modem, one router, layer 2 only after that.

Also, picks of patch panel

 

[mxnerd]

Yeah. I think one of his router was getting an IP address from ISP, and only devices that connected to that router were able to get online.

He needs to decide which one router will be used as main router and connect it directly to the modem he bought. Then put all other routers into AP mode.

 

[JackMDS]

Using Wireless Routers (or Modem/Wireless Router) as a Switch with an Access Point - http://www.ezlan.net/router_AP.html

 

[dave_the_nerd]

ipconfig output from devices when they work and when they don't, please.

 

[bruceb]

He should go: Cable Modem, Router, Switch, Access Points (if needed) .. And check in the main router how many large the IP range is that it can generate. ... He also does not require 3 routers ... that only causes troubles. 1 router should be enough. If needed you can use the managed switch to seperate certain devices to certain IP ranges.

 

[Rifter]

Larry nailed it buddy need to fix network layout.