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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."
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
The only title of honor that a tyrant can grant is "Enemy of the State."
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.
P.P.S. I'm doing Science and I'm still alive.
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)
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...
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.
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I'm running DD-WRT 23v2 on two Buffalo WHR-HP-54G routers, and I never have to reset them. However, I did have to update their configuration from the default settings in order to make them reliably stable. With the default settings, I would have to reset them occasionally. I changed the "maximum ports" from the default of 512 to 4096, and changed TCP and UDP timeouts from the default of 3600 seconds to 120 seconds. The reason for this (as stated in the DD-WRT help documentation) is that P2P apps often open many ports without closing them properly. These settings allow the router to handle that kind of usage much better.
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 :)
"He may be mad, but there's method in his madness. [...] It's what drives men mad, being methodical." G.K.Chesterton
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?
Here's two: Soekris, Mikrotik/Routerboard.
I've found that to be true. Where I live, the summer months bring terrible thunderstorms. If there's ever that lightning strike that causes the lights to flicker, the internet always "goes down". Every time, it's always been fixed by unplugging and re-plugging the power to the router.
Agreed on the power problems. I'm the engineer for an ISP here too and we also run into problems with our residential FWs. We were reselling D-Link but have switched to LinkSys. Both of them exhibit problems with power fluctuations. My parent's live in our service area, far from the paved roads. They are literally the last meter on the line. They get browns often. The usual outcome is that the router freezes hard. Rebooting does not fix it. The only fix appears to be a week or so with no power. The device eventually starts working again. We resell 350w UPSs to our users but our CSRs don't push them hard enough IMHO. Since most of our service area is rural we should really push them a lot harder. Personally I recommend Panamax surge strips. They actually open the circuit on undervoltage. Unlike most surge strips they actually cut off on overvoltage as well. They don't require the massive surges to set them off like most of the rest. Good stuff. I wish we sold them.
My off hand guess, Bittorrents. I've noticed with the WRT54G that I had for a while would have problems if you're running multiple torrents, and don't have any cap on how many inbound and outbound connections there can be (IE, overnight runs where you don't need to use any of your bandwidth :-) A reboot always fixed the problem - I assume it's either running out of memory, or running out of ports to work with (since each connection has a timeout of an hour, IIRC)
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it's simple, most router keep tcpip connections alive for 3600 sec or more (especially d-link one), so each time you establish a connection on a bittorrent client your router open a new one. After a few hours, sometimes a day or a few ones, it can become a problem very quickly as you might imagine. Just install dd-wrt or tomato and drop the timeout to 360sec, it'll do the job.
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.
Bottles.
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.
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My experience was nearly exact oppostie of yours, just chiming to say that anecdotal evidence is rarely accurate in practice. As others here have suggested, you might be more happy running the Linksys hardware with some 3rd part software; then again you seem happy with you d-link so maybe it isn't worth the effort for you.
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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.
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.
"You should always go to other people's funerals; otherwise, they won't come to yours." -- Yogi Berra
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.
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I second this. I have a D-Link Gamer Lounge (DGL-4300). This is the most stable router I've ever owned. Thumbs up on the QoS, stability and speed (GbE). If I were able to run 'uptime' on it, I believe it would say close to two years (I live in Florida, but it's on a UPS). Oh, wait:
Connection Up Time : 617 day(s), 12:04:53
Sick.
My last router was a WRT54GL that decided to brick itself after about three months of DD-WRT. I think I should agree with some of the above posts that offloading network services can help these routers, but I'm not sure. I run my own DNS and DHCP, so this router has never had to bear that load.
Also, jam the TCP timeout way down low. That will do wonders.
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I've had a WRT54G for almost two years. I've never had to reboot it, not even once. The trick was installing OpenWRT firmware.
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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
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Most often, actually, I've found that the cause is, gasp, Bittorrent. Fills up the NAT tables and they're not purged fast enough, unable to open / map more ports, effectively, no more connectivity.
That was rated funny, but truth be told I have seen Vista Laptops screw up networks often.
Especially with out Linux Fileservers, XP computers and Laptops can access them fine, but while the Vista machines sees the Fileserver in the "Network and Sharing Centre" as soon as you try to access the server Vista claims that the server "Does not exist or may be switched off"
Apparently there is a registry hack for this...
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I like the way you think. alix2c3 uses 6 Watts - a little more with a VPN card installed. I agree on keeping the wireless devices separate, they're just not gonna be rock solid.
This MS KB may help.
http://support.microsoft.com/kb/932134
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
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.
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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