Why Do We Have To Restart Routers?

jaypaulw writes "I've owned a WRT54G, some cheap D-Link home Wi-Fi/firewall/routers, and now an Apple Airport Extreme (100/10 ethernet ports). In the context of the discussion about the worst uses of Windows — installation in places where an embedded device is superior — I've gotten to wondering why it's necessary to reboot these devices so frequently, like every few days. It seems like routers, purpose-built with an embedded OS, should be the most stable devices on my network."

The most likely reason

You're doing it wrong.

Re:The most likely reason

Yeah, I've never had a problem with my rou

Re:The most likely reason

Mine never used to need re-booting until I added a Vista Laptop to the network???

Re:The most likely reason

I'm a network admin for an ISP, and we've been recommending UPSs for the frequent-reboot routers that our customers have. We've found that routers (especially Linksys) have a real problem with power fluctuations that most other systems and devices don't notice. A decent line-conditioning UPS might solve your problems, but a cheap one will suffice.

Also, could be the device is running out of memory, if your ISP is changing the properties of your connection a lot, or you might have a duplex issue causing a lot of retransmissions. . .

Just a couple of thoughts :)

Re:The most likely reason

mod parent up, as I came here to say that.

Also, the Linksys WRT54G up to version 4 was a fine router, plenty of memory, ran Linux, was very stable. Then Linksys decided that quality wasn't nearly as important as driving me batshit insane, and we started getting tons of complaints about users needing to reboot Linksys routers, which came _highly_ recommended from the geek squad over at worst buy.

The modern WRT54G, and anything past version 4, that doesn't have an 'L' in the name is an utter piece of crap, firmware revisions to the VXworks OS they now run have helped, but they are still lockup city.

Re:The most likely reason

I've noticed that ALL home routers at some point will require a power cycle, and not because they're bad, but because they all seem to occasionally lose their ability to provide DNS resolution. This isn't a problem on a LAN (like mine, obviously) which has a dedicated nameserver on the inside of the LAN, but for people who (like I once did) use their router as a nameserver.

Re:The most likely reason

All the Linux-based ones (decidedly few, admittedly) I have seen use the same DNS proxy (dnsmasq). I guess it's just not perfectly stable but I haven't seen a reboot anymore than once every few months.

I gave up on mine and turned it into a dumb PPPoE bridge. An OpenBSD box at the border handles the dirty guff of PPP sessions and NAT. Now my connection is perfectly stable and the modem never needs to be rebooted. To top it all off I trust the BSD box and the firewall I created on it more than I trust the router to do it properly.

Re:The most likely reason

Also, the Linksys WRT54G up to version 4 was a fine router, plenty of memory, ran Linux, was very stable.

Yeah, I have a 1.1, which I didn't even know until right now (checked the sticker), and I don't think I've rebooted that thing once in the entire time I've owned it. It's been running continuously right now for at least six months 24/7, and before that had a stint of probably 2 years uninterrupted. (I was forced to use Verizon's POS FiOS router for a little while.)

I was about to leave a comment wondering what the hell the submitter was talking about, because to me the WRT54G is probably the most stable router that exists. It really couldn't *be* anymore stable. But I didn't realize there were such problems with version 4 and above.

USR8054

US Robotics 8054 (USR8054). At least it has the decency to reset itself though throughout the day. Saves some manual labor I suppose.

Because they are cheap

Fast, Stable, Cheap - pick two.

Buy one that works.

I have a pair of Apple Airport routers, and the only time they get rebooted is when I change settings and restart them. That happens whenever I want to let another computer use my network, about every couple of months.

-jcr

Re:Buy one that works.

Yeah, I've used Apple Airports (previously, the "UFO" kind and currently, the Extreme (1Gb ports) and Express (for my home theater) and have never had to do "therapeutic" reboots on them.

But I have been irked due to having to reboot the router to make even the slightest of config changes - such as changing its syslog destination or adding a port to the forwarding table. You'd think that these and other operations, short of a firmware upgrade, could be handled without a full-blown reset, but apparently not. One has to wonder why that is so in this day and age.

Re:Buy one that works.

So you are lucky. My Airport Express needs to be rebooted from time to time (nothing damning, the express sometime stands month without needing it). My previous UFO Apple Airport also needed to be rebooted (and much more frequently than the Express).

The symptom on the Express are that DNS queries stop working. I can ping it, ping my DSL modem, and ping website for which I have IP. I can nslookup into my provider DNS. I cannot lookup into the Express DNS.

Another issue is that sometimes, I start getting more and more lag. Rebooting the mac or the DSL model doesn't fix it. But I discovered, amazed, that rebooting the express fixed it.

Btw "Buy one that works" is an extremely arrogant comment. Those units work for you, it does not prove it works for anyone else.

Resets aren't necessary.

Bought a Buffalo router and flashed it with DD-WRT. The only time the thing reset was when the power went out. If you're restarting your router every few days, I'd suggest looking into your config for the problem.

TCP Timeout

TCP connection timeouts on some routers default to 3600 seconds or one hour. So, when you use some Bittorrent or such, opening lots of connections, your router keeps these connections (even after disconnection) in its memory for up to an hour. It fills up and your router grinds to a halt, opening connections very slowly.

There's other timeouts too, but I'm not sure exactly what they do. Firmware like HyperWRT lets you change these timeouts to something much shorter, like 90 seconds, which typically prevents lock-ups like that.

(I'm actually not 100% sure that this is the sole cause for router lock-ups)

I never have to

Not to be a dick, but I use a wrt54g with tomato firmware and it's about the most stable and powerful (QOS is great on it) router anywhere close to the consumer price range.

I never have to restart my DSL router or Vonage router either, and I've kept all this stuff up 24/7 often with heavy use for years at a time.

If you're restarting networking stuff all the time, perhaps you've misconfigured it...

bad hardware

The hardware on your router might be failing, power supply or whatever. I had the same problem with a DSL modem once, it eventually just outright died. The new one I bought (netgear DG834G) hasn't had to be reset once.

A $50 Router Stable?

Most routers are cheap. (Apple's is overpriced-cheap; the point stands.) A bunch of them are free after rebates. Considering that, it's a wonder they keep running for more than 5 minutes. They come off the same assembly lines as those Norcent (who?) $15 DVD players.

You can buy reliable routers of course, from the C company, or the N company, or the J company, or a couple others. That's what corporations buy. What I wonder, though, is whether there's a middle ground: a "pro-sumer" router. Maybe somebody has got some suggestions.

It shouldn't be...

I've gotten to wondering why it's necessary to reboot these devices so frequently, like every few days.

It's cheap, fast development... Not bothering to pay attention to correctness, not watching for memory leaks, etc., etc.

It shouldn't be that way, of course. I got an old K6-2 system, underclocked it to 100MHz, removed CPU fan and replaced the PSU fan with a very slow and quiet model to make a nearly-silent 8watt system. Then installed OpenBSD on a 32MB CF card (stripped of unnecessary binaries for size, but otherwise completely normal), and have been using that for years. It will run indefinitely, without a reboot. My record for uptime so far is 5 months, and it's only that short because of power outages, and I don't feel the need for a UPS for my router...

It seems like routers, purpose-built with an embedded OS, should be the most stable devices on my network.

There's nothing about being "an embedded OS" that should make it any more or less stable.

The problem is..

...the expectations of the user. Newsflash: when you buy cheap crap it is going to perform like cheap crap.

I'll tell you why ...

crappy firmware. I flashed my WRT54G V4 with Tomato and haven't looked back. Also haven't had to reboot it in the past year or so that I've been using it, other than the occasional update. Tomato's developer obviously knows what he's doing: compared to the stock Linksys firmware he's lightyears ahead. And he's just one guy, you'd think a company with the resources of Linksys could do an even better job.

Crap hardware

Cheap "embedded" devices like routers and NAS-es routinely have extremely bad hardware. The competition apparently is so fierce that cutting corners of everything, from basic motherboard-like functionality to network and disk controllers is ubiquitous.

I'm occasionally doing hardware reviews for a local IT magazine and it's unbelievable what you can actually buy today as a bona-fide good equipment even from "brand name" companies. CPUs are usually ARM or AMD GEODE (You think VIA is slow? Think again. - Not to say there isn't a place for slow CPUs, only that this isn't it.), network controllers are cheap Realtek's and I don't know what they use for disk controllers (probably parts of the CPUs "companion" chipset) but it sucks.

I've seen "gigabit" network controllers on NASes that actually negotiate gigabit speed, although they are connected to buses and CPUs that break a sweat even at 100Mbit/s speeds. NASes that accept 4 drives cannot service reads on even one drive at more than 15 MB/s - introducing RAID (especially RAID 5) into this setup slows things to a crawl.

Practically all of these devices use Linux, because it's free (as in beer). They usually (I'd say 90%) don't acknowledge or obey the GPL.

It's a sort-of reverse "best scenario" for Open systems (and Open source). The manufacturers have a choice between something like this:

1. They'll design special ASIC-like functionality which will do one thing only and do it fast and stable.
2. They'll use cheap off-the shelf hardware and software which is generic.

The first choice is represented by "truly" embedded devices like ordinary small, unmanaged Ethernet switches (with which I have suprisingly good experience), but apparently it's too expensive to scale it to "smart" devices that have to support many features so everyone opts for the second one. You can (and this is verified!) build yourself a small managed router or a NAS device like the ones sold at every el-cheapo computer shop with the same cheap generic components, and the resulting device will be just as sucky.

Creating a router or a NAS just like the above but with "proper" hardware (a Duron 800 MHz based system will be excellent) won't even cost you significantly more, but will deliver orders of magnitude better performance.

Re:Maybe it's not the router...

If a client is able to cause a router to crash then there is something wrong with the router design.

Re:Good question.

If you have frequent power interruptions, aren't they rebooting your router frequently?

/just askin'.

Re:My theory...

I base this on absolutely nothing, but my primary suspect is the cheapskate power supplies that these devices come with. However I've never cared enough to test it out.

I think you're right. This seems to be especially common on D-Link routers. I used to run a DI-624 which was stable for years, until one day it just started rebooting itself. Did it infrequently at first, but progressed to the point where it rebooted continuously and was unuseable. Poking around, I discovered that the AC adapter (power brick) was not only VERY warm, the plastic shell was actually deformed a little on one side. I replaced the AC adapter, and the router worked good as new... until a few years later, when AGAIN it started rebooting, then stopped working entirely. And AGAIN, the AC adapter was at fault (totally dead this time). And again, replacing the AC adapter resurrected the DI-624.

It seems to me that the manufacturers of residential-class routers really skimp on the power supply, or at least D-Link does. The AC adapters they've bundled in recent years are smaller than a deck of cards, yet I'm supposed to believe that they can put out 3 amps of current at 5VDC indefinitely?