[ Home Networking Filter ] Why must I restart my wireless router every hour? Or, what am I doing wrong in the implementation of my home network?
July 21, 2009 6:33 AM   Subscribe

[ Home Networking Filter ] Why must I restart my wireless router every hour? Or, what am I doing wrong in the implementation of my home network?

So, I've got a home network that's somewhat complicated. It's composed like this:

Cable Modem -> Router #1 (Wired only) -> Router #2 (Wireless)

The household has a few devices that utilize the internet connection via ethernet cables from Router #1. We also have anywhere from 1 - 5 home computers (Both Windows & Mac), as well as an iPhone, connecting to the network via wireless connection through Router #2.

You might be asking yourself at this point, "Why the two routers?" This is a great question, and I believe it is an attempt to create a barrier between the IP addresses of the computing devices in the household from the internet as a whole. From how its been explained to me, the IP address of the devices are masked in this fashion by utilizing an IP address externally that is different from what is utilized in the home network internally. (Bonus points: Can you tell me if this is an effective course of action?)

As the title of the post suggests, our devices have trouble retaining a functioning connection with the internet. At some point in our usage, we will notice that data transfer stalls (web pages fail to load, downloads fail, etc), and although the wireless functions of our devices report a connection to the wireless router (and the IP address obtained via DHCP (automatically) is the same as the beginning of our respective sessions), it seems no data is being actually relayed to our machines.

Can you tell me what is happening inside our home network? Too many devices (and is there a limit to how many devices can wirelessly access a network at any given time)? Help a thoroughly confused Metafilter junkie!

Thanks in advance to everyone who takes the time to read and contemplate our predicament!
posted by platosadvocate to Technology (15 answers total) 6 users marked this as a favorite
One router doing DHCP is sufficient to allow you a private set of IP addresses.
Do both your routers do DHCP?
posted by Obscure Reference at 6:58 AM on July 21, 2009

" "Why the two routers? ... [explanation of NAT] ..."

The explanation you are given for this sufficiently explains why you would use exactly one NAT router but not two. There's pretty much no legitimate reason to use two NAT routers in a household, so someone is confused. Most likely that someone is whoever thought two routers were a good thing in the first place.

Option ONE: Make sure the second router isn't actually routing at all: have a LAN (not "WAN") port plugged in to a LAN port of the first (wired only) router. Have nothing plugged in to the "WAN" port of the wireless router. Disable the DHCP server on it. Give it an IP address on the other router's network so you can manage it as needed.

Option TWO: Unplug the wired router. Wrap it up in some bubble wrap. Put it in a box in the garage. Plug the cable modem into the wireless router and configure it properly.

Having done one of these things, you have eliminated the most irrational parts of your network design, and can then focus on which components are actually failing as opposed to merely catastrophically misused.
posted by majick at 6:59 AM on July 21, 2009

Your explanation.... ("the IP address of the devices are masked in this fashion by utilizing an IP address externally that is different from what is utilized in the home network internally.")... is roughly accurate, but you dont need 2 routers to accomplish that. You could replace both Routers with just one that does both wired/wireless and have the same protection.

What make/model are your 2 Routers?... More important question: are your two Routers both handing out IP addresses in the subnet? (Router 1 is using subnet 192.168.1.xxx and Router 2 is also using subnet 192.168.1.xxx).... if that is true, then that could be your problem. Both Routers are trying to manage the same subnet (192.168.1.xxx) and conflicting with each other. Can you get into the web-management page of Router #2 and switch it from "Router" mode to just "Access Point" mode ? (that would be the preferred solution if you cannot afford to replace both Routers with 1 combination Router.

The other theory might be that you are getting some wireless interference. Get into the web-management page of Router #2 and see if you can find what channel the wireless is on. ( From the factory most wireless routers are set (I believe) to channel 1, 6 or 11) Best course of action is probably to turn your wireless router OFF (unplug it).. use a laptop and an application like iStumbler to get an idea of other wireless signals around you (and what channel they are on).. then you can reconfigure yours so it doesnt conflict.
posted by jmnugent at 7:02 AM on July 21, 2009

Why must I restart my wireless router every hour?
Consumer grade wireless routers are pretty hit or miss. Sometimes you get a good one, sometimes you get a weak one. Consider replacing it.
posted by Liver at 7:02 AM on July 21, 2009 [1 favorite]

Oh, also:

"is there a limit to how many devices can wirelessly access a network at any given time"

None that you will run into as a household. The practical limits on number of devices are much higher than you could reasonably own in one house. If someone (hopefully not the same clueless person who deployed two routers instead of a router and a WAP) is trying to tell you your problems are "too many wireless devices on the network" they're full of crap. At worst the number of active devices will make it slower, but not cause failure.
posted by majick at 7:03 AM on July 21, 2009

I'm with Liver on this one. I had a cheap Belkin POS that required multiple restarts per day, got sick of it, and bought a WRT54GL from newegg (it was cheaper than $80, they just can't advertise their price). Haven't had any problems since.
posted by ArgentCorvid at 7:09 AM on July 21, 2009

Two issues:

1) Simplify the network. As others have pointed out, two levels of NAT is not a good idea and will break some applications. NAT is nasty enough going through it once, don't make your packets go through it twice. If you're not using both routers with NAT enabled (just using the wireless one as a bridge), it's still redundant unless they're physically separated by some great distance and giving you better wireless reception than you'd otherwise get as a result.

If possible, get rid of the wired router and use a single wireless one for everything.

2) If it was the wired router that was failing, pat yourself on the back at this point because you're done. If it was the wireless one, unfortunately you will probably need to replace it.

Sometimes, consumer-grade networking equipment fails because it's inadequately cooled, and you can make it more stable by installing a small fan into the top of the case. This requires a Dremel, plastic cement, and soldering skills. I'm honestly not sure if it's worth it, unless you have a very nice router.
posted by Kadin2048 at 7:13 AM on July 21, 2009

Yea, I almost guarantee you've got DHCP issues and I'm actually amazed this setup works at all.

If you don't have any wireless devices, stick with wired. Switch that if you do. If you have wifi and you need more plugs in the back, what you're looking for is a switch. (which will plug into one of the slots on the back of your router and give you 2-6 more plugs.)
posted by TomMelee at 7:25 AM on July 21, 2009

Your idea about the two routers is fine. From my understanding you're running NAT within NAT, which does make sense in the case of a wireless network since it will isolate the wired network from badness other people might choose to commit on your wireless network. The NAT on the wireless network makes it much harder for traffic between your wired computers and the internet to be redirected out onto the wireless side of things.

It's far more likely that your router is just broken. Unfortunately these things are insanely difficult to troubleshoot in any way other than "just replace things until it's better". So definitely try replacing the wireless router. Or swap the wired and wireless routers, if they both have similar capabilities. The wireless could be funky on one, but the wired part of it might be ok.
posted by kiltedtaco at 7:44 AM on July 21, 2009

I agree- there is probably some limited security benefit to having a second layer of NAT. If someone is smart enough to be able to break through NAT, they might not be smart enough to break through a second layer. But they probably are. At best, it slows them down a little. At worst, it breaks some things.

Definitely look at the DHCP thing as others have suggested. Even if all your clients are only connected to the second router and it is doing all the DHCP work, the actions of the intermediate router in getting a DHCP address from the cable modem and giving and address to the secondary router might be causing trouble. I suspect that it's probably something like that- when the intermediate router has to renew an address, it probably drops the current NAT table and starts from scratch. But the secondary router doesn't know about that and keeps trying, and breaks.

(In theory, since each router is on its own subnet, you aren't getting the issue of competing DHCP servers. Unless the intermediate router is giving addresses to the secondary router in the same subnet as the secondary router is giving out. That breaks routing. Just changing the subnet for one of them might be enough.

I had that situation with my own setup- I set up a VPN server on my router, so I could access my network from the outside world. Except, it wouldn't work depending on where I was. Turned out that it only worked when I was on a LAN that had a different subnet than my own router. I changed my internal network to a more obscure subnet, and that restored functionality.)

If you want to keep the two router setup, I'd recommend this: set the intermediate router to be the DHCP client from the cable modem. But turn its DHCP server off. Give the secondary router a fixed EXTERNAL address, in a different subnet (192.168.1.* versus 192.168.2.* for example), and have it be the DHCP server for the external network.
posted by gjc at 7:48 AM on July 21, 2009

Forgot this- it might be an urban legend, but I've heard tell that consumer grade networking devices don't like being too close to other devices. Something about putting out electronic interference. It might solve your problem to just arrange the devices to be a little father apart physically.
posted by gjc at 7:51 AM on July 21, 2009

While your stated reason for using two routers doesn't make much sense, there is no reason that your setup can't work as long as it is configured properly (I maintain a very similar setup in a different situation). The easiest fix is often, in my experience, to let the routers run a little cooler. Separate the modem and routers from each other and get them into a location with good airflow (and not too close to any computers). If feasible, stand them up on their sides. If that doesn't solve your problem, then look into your configuration.
posted by ssg at 8:36 AM on July 21, 2009

After reading these answers, I'm feeling less bad about my network setup method of "randomly try various things until it works."
posted by diogenes at 10:15 AM on July 21, 2009

Thirding double nat. What you need to do is put that wireless access point in gateway mode. Make sure it is not doing NAT or DHCP.
posted by damn dirty ape at 10:30 AM on July 21, 2009

Are you using P2P software heavily, especially BitTorrent? A lot of cheap router operating systems will choke when they have to deal with lots of simultaneous connections. If this applies to you, try decreasing the maximum allowed number of connections per client.

Running two layers of NAT provides no extra security, it just adds a second point of failure.
posted by teraflop at 7:08 PM on July 21, 2009

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