Switch + NAS not working on home network

[t3ch]

I feel pretty stupid having to ask for help on this but I give up trying to figure this crap out... any input would be much appreciated.

TLDR:
devices on a basic switch can't access the internet. IP's are out of scope, dns is blank, gateway is incorrect... points to a 192.168.100.x network instead of 192.168.1.x, have to use static to work. is there a setting in the router that needs to be enabled?


FULL SCOOP:
Setup:
cable -> modem -> router -> devices (switch #1, switch #2, NAS)
(comcast -> somemodem -> n66u w/ dd-wrt -> TL-SG108, some old netgear switch, Qnap TS-420)

What works:
- ethernet plugged directly into router
- desktops plugged into switch #2
- wireless

What doesn't work:
- devices on switch #1
- NAS

Troubleshooting:
- 2x brand new routers
- 2x brand new switches (TP 5-port and 8-port)
- cable swaps
- rebooted all connected devices + power cycled networking equipment dozens of times

Devices on switch #1 are receiving IP's out of the range of the router, blank DNS, and the wrong gateway. If I set static info it works, but I shouldn't have to do that.

What's weird is the NAS is plugged directly into the router but is getting the same out of range IP's as if it were plugged into switch #1.

 

[ch33zw1z]

What IP configs are you expecting, and what are you geting when it's wrong? Can you post some IP config outputs?

What's the Comcast modem in use?

 

[Fardringle]

Do you have a VLAN configured on the n66u router? If so, and that switch (and then the NAS when testing) are plugged in to the VLAN port on the router, what you are seeing is exactly what is supposed to be happening, especially if the VLAN is not configured properly.

Try connecting the "problem" switch to a different port on the n66u and see what happens (or just log in to the router and check to see if you have a VLAN set up).

 

[t3ch]

What IP configs are you expecting, and what are you geting when it's wrong? Can you post some IP config outputs?

What's the Comcast modem in use?

I'm expecting something along the lines of

IP: 192.168.1.110
DG: 192.168.1.1
DNS: 192.168.1.1

but am getting

IP: 192.168.100.10
DG: 192.168.100.1
DNS: 0.0.0.0

The router range is 192.168.1.100 through 192.168.1.150. I know 192.168.100.1 is the address of the modem, but I don't understand why the router is randomly being ignored by some devices but not others, or how they're even getting that range to begin with.

The modem is a basic motorola, not one of the newer fancy AiO modem/routers.

Do you have a VLAN configured on the n66u router? If so, and that switch (and then the NAS when testing) are plugged in to the VLAN port on the router, what you are seeing is exactly what is supposed to be happening, especially if the VLAN is not configured properly.

Try connecting the "problem" switch to a different port on the n66u and see what happens (or just log in to the router and check to see if you have a VLAN set up).

I don't have any configuration on the router besides wireless passwords, fresh dd-wrt install. Also had the same problem on a linksys ea6700 with the same setup (on cisco firmware), so I don't think there's a software problem that I'm inadvertently entering anywhere. I actually bought an Asus AC68R this morning (which of course goes on sale right after I buy the N66U, and for less) so will do more port testing in a bit.

 

[JackMDS]

Your Modem is Not Fancy but it is probably a Modem/Router and by adding the Asus as a Router you get double NAT.

In general.

Option 1 (the best) - Google the term "configure the (Modem/Router Model) as a Modem only.

If you find solid instructions, try it and then you can use the Asus as a regular main source Wireless Router.

Option 2 - Configure the Asus to work as a Switch with an Access point as part as the Modem/Router configuration.

http://www.ezlan.net/router_AP.html


Option 3 - (the worse) - Doing for you are panning to do and ending up with Double NAT and two independent Subnets/Networks.

 

[t3ch]

just checked out the settings on the modem and it's enabled to be a DHCP server... no way to disable that. Shouldn't DHCP be left to the router while the modem simply grabs the WAN IP, or am I misunderstanding what it being a DHCP server means? perhaps that just means being able to pull the IP from the ISP?

we've been using the exact same modem for the last 4 years and it's never given me any problems. network has been the same devices, and as a matter of fact was working in this exact configuration several weeks ago until one day it randomly started giving me the issues in the OP.

and now even devices that were previously working aren't working with DHCP on the new router... lol. on a static right now to post. wireless works OK, wired giving out garbage like post #4. this is ridiculous and stupid.

 

[ch33zw1z]

What model Modem are you using?

Have you attempted a full power cycle on the modem? (including disconnect of the coax)

Are you leasing the modem or have your own? If leasing, get a replacement from comcast.

 

[t3ch]

surfboard sb5101 - http://www.newegg.com/Product/Produc...82E16825122003

have power cycled dozens of times, haven't actually yanked the coax out though, will try in a bit

leasing. asking for a replacement is where I'd been leading before even posting but figured I'd cover the bases first. it seems like a simple enough dhcp problem, assumed user error

 

[ch33zw1z]

The router's WAN should be DHCP, but you should not be getting 192.168.100.x's. Try pulling the Coax for the full power cycle, and don't plug in the router until the modem looks all set.

 

[Fardringle]

The Surfboard SB5101 does have the ability to act as a DHCP server and will pass out 192.168.100.xxx addresses when it does, but it will only do that if it does not have a valid WAN (ISP) connection, or if it is malfunctioning.

 

[t3ch]

- power cycled surtboard modem w/ no coax, same problem
- got new modem, same problem (http://www.amazon.com/uBee-DDM3513-D.../dp/B005Y1UFIM)

 

[ch33zw1z]

If you plug in directly to the modem with a workstation, what IP do you get?

 

[t3ch]

looks like it got the wan ip

ip - 76.104.x.x
subnet - 255.255.254.0
router - 76.104.2.1 (this is different from the actual IP above)
dns - 75.75.75.75

 

[vbuggy]

So what's the router reporting for the WAN link when you plug the modem in? The same?

 

[t3ch]

WAN

Configuration Type
Connection TypeAutomatic Configuration - DHCP
Connection Uptime0:00:06
IP Address98.249.x.x
Subnet Mask255.255.255.0
Gateway98.249.30.1
DNS 175.75.75.75
DNS 275.75.76.76

 

[t3ch]

have we given up on my stupid, stupid problem?

 

[Mushkins]

Unplug it all, turn it all off.

DO NOT PLUG THE MODEM BACK IN, LEAVE IT POWERED OFF, REMOVE THE ETHERNET CORD.

Plug the router in, wait 2 minutes to let it fully boot. Plug the switches in, wait 2 minutes for them to fully boot. Turn your devices on one at a time and record their IP settings. If anything is still getting that 192.168.100.x address, ping 192.168.100.1 from that device and see if there is a response. If there is, the next step is to track down that device.

 

[ch33zw1z]

have we given up on my stupid, stupid problem?

You're pretty much to the point of problem isolation. One step at a time, one device at a time, and verification with each step.

 

[avos]

Out of curiosity do you have the Ethernet that is coming out of the modem plugged into a lan port on the router instead of the WAN port? That is the only setup that I can imagine a 192.168.100.x dhcp response getting to a device downstream of the router.

Edit: Alright that can't be if you are getting the WAN configuration that you posted in a later post. Other than that all I can think is if the switch is somehow between the router/modem or if the router is set up as a bridge with the modem instead of as a gateway.

 

[t3ch]

Out of curiosity do you have the Ethernet that is coming out of the modem plugged into a lan port on the router instead of the WAN port? That is the only setup that I can imagine a 192.168.100.x dhcp response getting to a device downstream of the router.

nah the router has a specific "INTERNETS GOES HERE" port

 

[t3ch]

got around to doing the whole plug, reset, retest today

stupid resolution... TV box was taking over DHCP

we have an xfinity cable box (RMG 150N) and sure enough when I plugged it back into the entertainment center switch all the 192.168.100.x IP's popped up again. when I installed the new switch (with more ports) I must have hooked it up for the first time, I thought it was already plugged in before. dumb dumb dumb.