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Why Do We Have To Restart Routers?
Posted by
kdawson
on Sat Jul 12, 2008 06:43 PM
from the buildup-of-bogons dept.
from the buildup-of-bogons dept.
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."
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From the article: "Thanks to VMWare Windows is spreading throughout the datacenter. And, of course, there is only one operating system to use if you are dependent on Microsoft apps like Outlook, Word, and Excel. While I have joined the chorus of security folks who rail against the Microsoft Monoculture I still cannot believe some of the uses for Windows. Some of them are just downright silly, some you may claim are criminally negligent." Note: I'm making no claim of criminal negligence!
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The most likely reason (Score:5, Funny)
You're doing it wrong.
Re:The most likely reason (Score:4, Insightful)
That's what I was thinking. I have a linksys wrt-54g or whatever they are running ddwrt and I've probably has to reboot a handful of times in all the years I've had it.
Parent
Re:The most likely reason (Score:5, Funny)
Mine never used to need re-booting until I added a Vista Laptop to the network???
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I hope this explains a few things. (Score:5, Insightful)
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Re:I hope this explains a few things. (Score:5, Funny)
If I had modpoints, you could have them all for that.
Parent
Re:Vista (Score:5, Informative)
Same here. The condition that tripped the problem went as follows:
My laptop = Ubuntu (latest)
Wife's laptop = Vista Home Premium.
Both wireless.
We're surfing, everything is running great. I'd hit a site that had lots of images all on one page (think Fark's 'Photoshop this pic' page')
Bang, network goes dead.
I'd restart the router and my box would come back online no problem. Vista would not re-establish a connection. Repair (or whatever it's called in Vista) failed. We'd need to reboot her computer.
Searched the web and found that this same problem happens and seems to be related to the router.
Switched to a Netgear VPN824V3 and the problem has pretty much disappeared.
Parent
Re:The most likely reason (Score:5, Informative)
This MS KB may help.
http://support.microsoft.com/kb/932134 [microsoft.com]
There is also an MS KB related to the broadcast flag which may be what is being referred to.
http://support.microsoft.com/kb/928233 [microsoft.com]
Parent
Re:The most likely reason (Score:5, Informative)
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 :)
Parent
Re:The most likely reason (Score:5, Interesting)
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.
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Re:The most likely reason (Score:5, Insightful)
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.
Parent
Re:The most likely reason (Score:5, Interesting)
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.
Parent
Re:The most likely reason (Score:5, Interesting)
Is that OpenBSD on a 12W device that sits silently on a shelf?
Personally I prefer to use a decent modem. I have a SpeedTouch DSL modem that seems to be more functional than most consumer routers, as well as being one of the more stable modems I've used on a marginal line. I connect my wireless devices to my network just on the switch side (use them as wireless access points and not routers). Very stable set up.
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Re:The most likely reason (Score:5, Informative)
Mine is, I have a Soekris net4501 running OpenBSD 4.2. Nice and quiet, low power, high reliability. And the smallest CF I could find was a 1gig, so I have the entire installation, sans X on that puppy. Full support for VLANS, OSPF, Pf, the works. All in a small, quiet, low power, albeit ugly green case.
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Re:The most likely reason (Score:5, Informative)
Mine is sitting on my server...
Have not rebooted it since I moved (~1 year)
really, I think it's power issues. This same router gave me tons of greif at my previous place, but when I moved I put it on the UPS and no issues since...
-nB
Parent
Re:The most likely reason (Score:5, Insightful)
DD-WRT on my WRT54GL, I've never had to reboot it for those issues. I even have a couple separate VLAN's set up, two DHCP pools on separate interfaces, etc. I've had uptimes of over 80 days before I tweaked something else on it that required me to reboot it.
It's not the hardware... it's the generic crap software that they run on.
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Re:The most likely reason (Score:5, Informative)
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Re:The most likely reason (Score:5, Informative)
The problem I've had with dd-wrt and torrents is the max tcp connections is by default very low. Not something you would notice under normal traffic, but during swarms it can fill up fairly quickly.
It give the appearance the unit has locked up since it is difficult to establish a tcp connection. These will bleed away eventually and allow a connection to be established.
I just set the max number of tcp ports and it fairs fairly well using bit torrent now.
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Re:The most likely reason (Score:5, Informative)
Also, jam the TCP timeout way down low. That will do wonders.
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Re:The most likely reason (Score:5, Informative)
Linksys is the one manufacturer that's on my "never" list. My previous employer used to use their hubs and cascaded them into a network switch. The darn things kept losing track of what MAC addresses were hanging off them and refusing to route traffic. You only have to have one complete and utter failure like that to be written off in my book.
That said, I've recently also written off Netgear. After about my fourth or fifth Netgear card went dead (I think I have one left that is still functioning after three or four years), I started avoiding their cards like the plague. Then, I bought one of their consumer hubs a couple of months ago and it was dropping something like 80% of the packets that went through it (between any two devices including upstream). I took it back to Fry's and replaced it with a D-Link and it worked flawlessly. (And no, I didn't have something hooked up to the uplink and the non-uplink port beside it. Been there, done that.)
Bottom line is that after three hard drive failures in the course of a little over a month (yes, I have a third Seagate drive misbehaving massively, randomly corrupting data), I've pretty much come to the conclusion that nearly all electronics built today are mass-Chinese-manufactured crap that barely works and doesn't even do that for very long. Very sad, really.
Parent
Re:The most likely reason (Score:5, Interesting)
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.
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Re:The most likely reason (Score:5, Informative)
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Re:The most likely reason (Score:5, Informative)
In theory, none of those routers should need a UPS, just a better AC-DC converter perhaps with a bigger capacitor across the DC lines. I've never investigated the quality of the wall warts they supply with routers, but my guess is they are very cheap and simply don't handle voltage fluctuations as well as they should.
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Re:The most likely reason (Score:5, Informative)
Now I have a Buffalo G125 with dd-wrt and is AMAZING (good luck finding one of them these days in the states after their legal troubles though). The last time I had a necessary reboot was when I upgraded the firmware (to enable cool things like bandwidth graphs). Sometimes I will reboot it when it is not necessary--such as when comcast has some sort of unknown network issue so my first thought is to start powercycling things until I remember the cable modem's IP and see that there are connection errors in the log. Other than that, rock solid stable with 5 active users and a good deal of game/torrent traffic.
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Re:The most likely reason (Score:5, Funny)
Yeah, I've never had a problem with my rou
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Re:The most likely reason (Score:5, Funny)
Yeah, I've never had a problem with my rou
You know what, those jokes are fucking la
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Re:The most likely reason (Score:5, Funny)
Oh, very simple: I have a fr
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tcpip timeout, too many connections (Score:5, Informative)
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Re:The most likely reason (Score:5, Informative)
So pay $70 to get a WRT54GL, then use some different firmware like DD-WRT or tomato on it. Cheap, and they even make installing it and all easy, as easy as the "normal" routers are to configure, and it'll get you those long uptimes.
If you don't like your crappy router, fix it. It's not that hard.
Parent
USR8054 (Score:5, Funny)
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 (Score:5, Insightful)
Fast, Stable, Cheap - pick two.
Buy one that works. (Score:5, Informative)
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. (Score:5, Informative)
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.
Parent
Re:Buy one that works. (Score:5, Informative)
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.
Parent
Re:Buy one that works. (Score:5, Informative)
Most likely, jcr is using MAC filtering [wikipedia.org] (capitalization == acronym; it has nothing to do with Apple's Mac computers). I have yet to use a consumer router that did not want to restart after you changed router settings, and adding a new MAC address [wikipedia.org] to the access list would require a restart. Hence, restarting the router when letting another computer use the network. Some people actually care about the security of their network; living in a major urban area with a lot of neighbors generally encourages it.
You may wish to look into using MAC filtering [wikipedia.org] and a strong WPA2 [wikipedia.org] password to protect your wireless network.
I also have a gig-E Airport Extreme, and it has been rock-solid stable for me; the only restarts have been for either changes I have made to the settings or for a firmware update. (I've done one of the latter since I got it.) It's been up continuously since it replaced a 10/100 wireless-G Netgear that constantly needed reboots, whenever I put any kind of load on my network. (It locked up constantly.*) If I hammer the Airport Extreme, it performs flawlessly. I still think that it was a great upgrade decision, but I'm sure that I'll get bashed as an Apple-fanboy because of it (most likely by people who can't differentiate between "MAC [wikipedia.org]" and "Mac [wikipedia.org]"). ;)
* To mitigate my Netgear bashing slightly: I've had nothing but success with wired Netgear products. The wired router by them that I used to have worked great, and their gigabit switch that I currently use has worked admirably well, without issue. I just should have gotten a wireless router from them that would have run Linux. ;)
Parent
Resets aren't necessary. (Score:5, Informative)
TCP Timeout (Score:5, Informative)
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 (Score:5, Informative)
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 (Score:5, Informative)
A $50 Router Stable? (Score:5, Insightful)
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... (Score:5, Interesting)
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...
There's nothing about being "an embedded OS" that should make it any more or less stable.
The problem is.. (Score:5, Insightful)
BitTorrent?? (Score:4, Interesting)
I had a WRT54GX for years that never needed a reset, until I started using BitTorrent. Then its 4KB (?) connections table would fill up and the device would hang. Had to build an OpenBSD firewall to handle the many active and inactive connections you get with BT.
You're doing it wrong? (Score:4, Interesting)
Now I've got an old PII with a CF as HDD running monowall and maximum uptime so far is about two months. It would appear that the modem is more flaky than the router so I've restarted it needlessly a few times. I'm inclined to think it's hardware causing problems when the router crashes on its own. It's a bare motherbord sitting ontop a cabinet with four NIC's (I had an abundance of NIC's but no switch) and it gets a bit jangled from time to time in its exposed position. I'm amazed that it works at all.
Try to limit the amount of open connections if you're running bittorrent and maybe the bandwidth too. If that doesn't help you should probably build your own router. m0n0wall works for me and I've heard good things about IPCop.
I'll tell you why ... (Score:5, Insightful)
Crap hardware (Score:5, Insightful)
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:
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... (Score:5, Insightful)
If a client is able to cause a router to crash then there is something wrong with the router design.
Parent
Re:Good question. (Score:5, Insightful)
If you have frequent power interruptions, aren't they rebooting your router frequently?
Parent
Re:Good question. (Score:5, Insightful)
Why DO you have to reboot your routers? Mine, including a WR54GT almost never require rebooting. Occasionally, after a power outage, it's necessary, but not very often. Maybe once or twice a year, and I live in Panama, where power interruptions come fairly frequently.
WTF? How did this end up +5 Informative?
The power interruptions are obviously regularly rebooting his equipment. Is it any wonder he doesn't need to reboot it himself?
Parent
Re:My theory... (Score:5, Informative)
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?
Parent
Re:embedded network devices (Score:5, Interesting)
Funny, I think everyone here has had to reboot their router to solve problems in the past. But, in typical slashdot fashion, 99.9 percent of the posts are people telling the author of the question that he is stupid, lacks intellectual ability, must be a high school drop out, or has some bastardized sexual persuasion that prevents his router from working.
As you say, it could be an unrelated issue that resetting the state machine fixes. In this case though I guess I superior device could do this on its own.
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