[HN Gopher] Every day at the same time, my internet dies for 1 m...
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Every day at the same time, my internet dies for 1 minute. How do I
investigate?
3:40pm every day my wifi loses internet access. My devices remain
connected to the network, but all traffic dies. Almost exactly 1
minute later everything is resumed. I have no idea what the cause
could be. How could I begin investigating this? I have a spare
Raspberry Pi and and old Android phone at my disposal, and some
programming competency.
Author : overallorder
Score : 257 points
Date : 2021-01-16 15:19 UTC (7 hours ago)
| ews wrote:
| Is your ISP att/fiber? I have exactly the same problem every
| night at 4am.
| dwt204 wrote:
| I am not an expert whatsoever. I just notice a similar thing
| happening at around the same time, the wireless and sometimes
| ethernet connection dies. Usually a minute up to three minutes
| the connection resumes.
| atomashpolskiy wrote:
| traceroute?
| [deleted]
| agotterer wrote:
| I had a similar problem once. The issue ended up being a router
| power cycle which occurred at the same time every single day. It
| took several days to diagnose. First, during an outage I tried to
| login to my router. Just because the internet was down the local
| area network should have been up. I couldn't access the admin
| panel for several minutes. Next, I started observing the lighting
| patterns on the router. I came to realize that it appeared to be
| restating itself for no good reason. In the end my internet
| provider replaced the router which fixed the problem. Tech
| support was pretty stumped. A few people on the internet
| complained about the same issue with the Fios router model I had
| (don't remember which one it was). Good luck! Let us know what
| the problem was if you figure it out.
| breckenedge wrote:
| I had a similar problem with my Asus router. Traced it back to
| it being scanned for UPnP every day at the same time. Something
| about the scan caused the router to crash and reboot. Disabled
| UPnP and the problem disappeared.
| jedimastert wrote:
| I love that almost everyone here has some sort of "family IT
| syndrome" but still got nerdsniped but the question
| zaidazmi wrote:
| Some routers allow to reboot daily at a set time. Worth checking
| the settings of your router.
| niklasmtj wrote:
| Did you check if your public IP changes after this minute? I
| don't know if this still happens but back in the past my router
| did this every 24h to get a new IP.
| rndgermandude wrote:
| A lot of service providers do this because they do not want you
| to host static services from your "dynamic" home IP, as they
| are selling "business" lines with dedicated static IPs. Or at
| least they used to do this for that reason. By now it's just
| some thing a lot of ISP do. I have seen other possible
| explanations like ISP claiming this is a "security" feature
| because attackers cannot have permanent access without always
| learning the new IP, which is supposedly somehow hard. This is
| pretty bull tho. If attackers have access to your system they
| could just run software signalling them back any IP changes.
| And even nmapping the entire IP space of an ISP to find a
| service you were hitting again is very feasible.
|
| Anyway, if the ISP does this, then you have to reconnect once
| every day (or sometimes every two days), and if you don't do so
| manually they will just cut your connection on their side and
| make you reconnect.
|
| My (German) ISP does that too, the one I had before did it, the
| one before did it as well.
| znpy wrote:
| If you can replace the ISP provided router with your own you
| should be able to renew the lease.
| njsubedi wrote:
| I can confirm this. The time is around 7:00PM and the IP
| address changes, and I have to log in again to some websites
| because my IP has changed. Downtime is approximately 2 minutes.
| pmiller2 wrote:
| This was my thought as well. It sounds like a 24 hour DHCP
| lease expiring.
| xbkingx wrote:
| I had the same problem with and older Netgear router. It turned
| out to be a bug in the scheduling settings. It had the ability to
| disable network access between specific times on a daily
| schedule. The feature was enabled by default, but no times were
| set to disconnect. You'd think that would mean the connection
| would never go down, but a firmware update changed that. Every
| morning at ~3:00am the network would go down for 1 minute.
| Disabling the feature entirely resolved the problem.
| detaro wrote:
| Sounds like standard reconnect every 24h, many ISPs do that.
| reset your modem at a weird time to get the interruption at that
| weird time in the future.
| bjeds wrote:
| This.
|
| I think the OP is so eager to get back online he sees 3:40
| every day and is using that timepoint as his troubleshooting
| clue.
|
| However If he were to disconnect 3:10 and then just be offline
| an hour until plugging the device back he would probably see
| the reset happen 4:10 going forward.
| ourcat wrote:
| Have you tried different WiFi channels?
|
| I had a similar experience to this years ago while working at my
| mother's kitchen table for while. The network would keep going
| dead and I had no idea what was causing it.
|
| Eventually, I discovered that it happened every time she used the
| microwave to heat up a drink or something.
|
| Changing to a different WiFi channel fixed it. :)
| bonestamp2 wrote:
| I came to suggest the microwave too. The 24h IP reset sounds
| more likely, but don't discount the microwave, they typically
| use the 2.4 GHz frequency (as do bluetooth and some wifi
| networks of course). So, if the 24h IP reset isn't it, try
| switching to a 5 GHz wifi network to see if the same dropout
| occurs. If that solves it, it could be a nearby microwave oven.
| analog31 wrote:
| One thing is to find out if something has a midnight bug, but has
| its internal clock set to something other than your actual time
| zone. I once committed a midnight bug in a manufacturing plant,
| and it took me a while to diagnose, because none of the PC's were
| networked, and I had never bothered to set the time on them. I
| puzzled over it until one of the operators said: "It always
| happens at the same time every day during my shift."
|
| Disclosure: I'm smarter now.
| Brian_K_White wrote:
| At 3:30, disconnect your router from your modem and connect a
| laptop directly to the modem. No wifi. Start a speed test or long
| video or something and just watch the modem through to 4:00.
|
| HAVE a separate modem and router.
| danesparza wrote:
| Many people have mentioned DHCP -- and a misbehaving DHCP client
| could certainly be the culprit.
|
| In doing some of my own network investigating recently, I
| discovered that services like Suricata will (by default) take
| down network interfaces and restart them when they get new rules.
| I wonder if something software on your router is doing something
| similar: Are you running Suricata or Snort?
|
| Also: Logs are your friend. If you have access, review the logs
| of your firewall / router / etc.
| rsyring wrote:
| Step 1: reboot all devices on the network: computers, router,
| cable modem (or whatever equivalent device your router plugs
| into).
|
| If that doesn't fix it, below is how I'd proceed.
|
| Use the trace route networking tool (google it, different syntax
| on different OS) to some known good public IP address. I usually
| use 1.1.1.1 or 8.8.8.8.
|
| This tool shows you the path your traffic takes:
| $ traceroute 1.1.1.1 traceroute to 1.1.1.1 (1.1.1.1), 30
| hops max, 60 byte packets 1 192.168.1.1 (192.168.1.1)
| 1.286 ms 1.386 ms 1.963 ms 2 192.168.11.1
| (192.168.11.1) 2.591 ms 4.342 ms 5.219 ms ...snip...
| 16 0.ae19.GW8.CHI13.ALTER.NET (140.222.230.223) 42.888 ms
| 35.742 ms 0.ae20.GW8.CHI13.ALTER.NET (140.222.230.225) 41.060 ms
| 17 152.179.105.202 (152.179.105.202) 51.913 ms 50.681 ms
| 55.442 ms 18 one.one.one.one (1.1.1.1) 70.087 ms
| 65.130 ms 53.607 ms
|
| The snippet above shows that I have two local devices
| (192.168.1.1, 192.168.11.1) my traffic passes through and 18
| devices total before my traffic hits the public IP.
|
| Run this command at 3:39. Then run it again at 3:40. Then again
| at 3:41. Compare results and that should give you a good idea
| which device is malfunctioning at that time.
|
| Some routers also have a ping command baked into them. If you can
| make it constantly ping 8.8.8.8, while you run the test above, it
| may help you. In the case where your traceroute stops at your own
| router, you can look at the ping from the router itself, and see
| if it also stopped:
|
| A) If the traceroute stops at your router, but the router ping is
| not interrupted, then something in your router is flaking out.
|
| B) If the router ping is also interrupted, then the problem is
| "upstream" from you. Maybe the cable modem (or whatever device)
| that is upstream from your router.
|
| If you decide the problem is upstream, contact your ISP. If it's
| local, investigate and/or replace the flaky device.
|
| HTH.
| ffpip wrote:
| Maybe your ISP resets your external IP at that time.
| uzgz wrote:
| https://www.ispreview.co.uk/index.php/2020/09/18-months-of-v...
| corysama wrote:
| Does your WiFi provide a way to monitor the real time bandwidth
| usage of each device? I was experiencing randomly timed outages
| for a while. Turned out to be our various phones and other
| devices randomly saturating my low upload bandwidth with cloud
| backups. That _shouldn't_ kill my downstream bandwidth, but it
| does.
| unilynx wrote:
| It doesn't kill your downstream directly, but you can't send
| the acknowledgements for the download fast enough if the upload
| is saturated. That kills your download speed
| dougSF70 wrote:
| I have the same wifi issue. At 3pm (approx) my comcast business
| wifi drops for a minute or two.
| olmideso wrote:
| If your devices are kept connected this means that your wifi and
| router are still active, probably the issue somewhere behind your
| router, either a connection or provider. But due to exact timing
| it's likely something on the provider's side and not just some
| connection issue. I would personally start with contacting them
| to investigate.
|
| You might also check the router's logs for that time, perhaps
| there's something useful information.
| uzgz wrote:
| Check this article. Might be some other faulty electrical device:
| https://www.ispreview.co.uk/index.php/2020/09/18-months-of-v...
| freitasm wrote:
| Are you on a xDSL service of fibre?
|
| On xDSL services, some monitored alarms may cause line problems
| when they "check in". In these cases an in-line DSL filter should
| do the trick.
|
| Another possibility is that some modem/routers have a "self
| healing feature" that is just really a restart. See if there's
| anything like this in the admin/system part of the configuration
| settings.
| rsecora wrote:
| First step check if the external wan IP address has changed.
|
| Second Check the logs of the pppoe daemon in your router. (If the
| router provides such logs).
| uncledave wrote:
| Try and get hold of your Internet/WiFi router's logs. The answer
| will probably be in there.
| milankragujevic wrote:
| @OP did you try calling support to report the problem? It's
| almost impossible to diagnose ANY internet problems (not related
| to your own equipment of course) and the ISP has tools and access
| to do it. In any case, it's much easier and faster to contact
| support.
|
| In my experience, even if I discover what is the problem, if it's
| on their side I still have to go through support to get it fixed,
| so I just wasted my time. And in most cases the lowest level of
| support doesn't even write down the information I give in the
| ticket, even if I send an email.
| jb775 wrote:
| Go to 192.168.0.1, log into your router/modem and see if there's
| an admin "Event Log"...could find some answers there.
| tekknolagi wrote:
| We had this problem in our house and it turns out it's because I
| accidentally plugged the modem into one of those auto power
| switches meant for turning off lights periodically.
| elliekelly wrote:
| Do you have xfinity by any chance? And are you using their x1
| combination modem/router in bridge mode with custom (non-comcast)
| DNS settings?
|
| Because the exact same thing was happening to me at the exact
| same time. I'm no networking expert but when I checked the logs
| it seemed that every day Comcast would try to "fix" my (not
| broken) DNS settings. I had been using mullvad DNS and open DNS
| as backup but since switching to nextDNS the issue has stopped.
|
| I don't know enough about networking or DNS to offer any
| explanation as to why.
| dpedu wrote:
| I have xfinity configured with custom DNS and used to have a
| somewhat similar problem. At the same time each day, DNS would
| stop working (but I could still reach plain IPs) for a couple
| minutes.
|
| It went away after I called them and had them "de-provision"
| and "re-provision" my modem. Basically deleting it from their
| system and readding it. For whatever reason, whenever I'm
| having chronic comcast weirdness, having them do this solves
| it. It sucks that this is the way things are.
| princevegeta89 wrote:
| Wow I have the same problem here. In my case I found out it is
| at&t themselves.
| kvhdude wrote:
| did you check your router (sys)log messages. Many of the routers
| will allow enabling debug logs as well.
| 29athrowaway wrote:
| This sounds like your DHCP lease is expiring and you have to
| request a new one each time it does.
| raarts wrote:
| Switch off you WiFi (and your modem if they're different). Stay
| up very late and switch them back on at 2am or so. Maybe the
| problem now occurs at 2am.
| dickfickling wrote:
| MY INTERNET HAS BEEN GOING OUT AT 3:40pm PT TOO!
|
| Sorry for the all caps. I just scrolled through my texts and saw
| the "internet out?" texts are at the same time.
|
| Hopefully that means it's a provider issue behind us. Wonder what
| we have in common?
|
| - South Lake Tahoe, CA
|
| - Spectrum Gig internet
|
| - Asus Zenwifi mesh
| [deleted]
| fisherjeff wrote:
| Hmmm my Spectrum Gig in OR doesn't go out at 3:40p but it does
| pretty much every day at 1pm. I was similarly excited to see
| this post...
| onionisafruit wrote:
| In my neighborhood it's shortly after midnight. Or so I've
| heard from my kids and neighbors. I'm never awake to notice.
|
| Also Spectrum, but no gigabit here.
| wasdfff wrote:
| My spectrum cuts out pretty reliably at 12:30am every night.
| Lets me know its time for bed.
| fisherjeff wrote:
| Now that, I could get behind: "Attention Spectrum user,
| cease doomscrolling at once and get some sleep"
| beaugunderson wrote:
| Spectrum in Huntington Beach, CA; ours does go out for one
| minute during the day as well though I didn't think to get
| systematic and note the times.
| amelius wrote:
| Get better hardware and software that properly reports error
| messages instead of hiding them.
| not2b wrote:
| It's probably the 24 hour IP reset, as many commenters have said.
| You could try time-shifting it to a time when you're normally
| asleep.
| derwiki wrote:
| Disconnect your wifi gateway and plug a computer directly in to
| your modem. Eliminate or prove the router as the problem source.
| the8472 wrote:
| Some german ISPs used to force a reset of home internet
| connections every 24h to trigger IP changes so that static IPs
| would remain reserved for the business tier. The time of the
| reset could be shifted by preemptively reconnecting at a desired
| time, they only reset the link after 24h of actual uptime.
| 0xTJ wrote:
| I get why they do it, but actually causing issues just to cycle
| IPs seems like a lot. I've had cases where I have the same IP
| assigned to me for quite a long time.
| aeyes wrote:
| They already did this on dialup and ISDN, back when routers
| didn't exist. When DSL first started appearing they just kept
| doing it. The idea was to not keep unused connections/IPs up,
| since you didn't have a router you would need to reconnect
| manually.
|
| Also, it made it harder to run servers until we had services
| like DynDNS.
|
| On newer connections it isn't common anymore, especially if
| you have a voice service.
| Lev1a wrote:
| On my family's FritzBox we can set the time for that connection
| reset. I think it's somewhere around 04:00.
| uzgz wrote:
| Second possibility: Did you connect a Sonos Device to your router
| using ethernet? If so, does your Sonos send on the same wifi
| spectrum your router does? My Play:5 sent on channel 11, so did
| my router, mesh repeater could not send to base while all
| connections appeared to be just fine.
| cvandebroek wrote:
| +1 on @detaro's message. Sounds like a 24h disconnect. Your
| router may have a feature to set dis/connect times manually ir
| you unplug/replug it at the time you wish to have the dis/connect
| to happen.
| xgbi wrote:
| Launch 'mtr google.com' on one of your devices (preferably
| connected via Ethernet to your router) a few minutes before the
| cut off, and watch what happens when the cut occurs. It will show
| you exactly which equipment on the route starts dropping.
|
| Although I suspect your ISP has a 24h lease and your modem
| renegociates at 3:40 everyday
| wjnc wrote:
| So then the trick is to forgo internet by disconnecting power
| from a few minutes before that time to the middle of the night
| and get power back? I do feel for the ISP's with this setup
| because the right thing to do would be to write in the
| installation manual: "Only install in the deep of night".
| milankragujevic wrote:
| Well they could 1) renew the IP before it expires or 2)
| reboot the modem remotely at 3:30am for example.
| hsbauauvhabzb wrote:
| Or assign a lease that expires at 0330 instead of a lease
| that expires in 24 hours.
|
| But I've not experienced similar in 20 years of dynamic
| ips.
| rantwasp wrote:
| it depends. depending on the dhcp implementation on the
| server side you may have the same problem (ie while you get a
| new lease it may expire at the same time). unlikely but I've
| seen some stuff when it comes to dhcp
| KronisLV wrote:
| Here's a summary from the man pages of _mtr_ , for those who
| are not familiar with the tool but maybe are reading HN on
| their phones so can't check it out: mtr
| combines the functionality of the traceroute and ping programs
| in a single network diagnostic tool. As mtr
| starts, it investigates the network connection between the host
| mtr runs on and HOSTNAME by sending packets with purposely low
| TTLs. It continues to send packets with low TTL, noting the
| response time of the intervening routers. This allows mtr to
| print the response percentage and response times of the
| internet route to HOSTNAME. A sudden increase in packet loss or
| response time is often an indication of a bad (or simply
| overloaded) link. The results are usually
| reported as round-trip-response times in milliseconds and the
| percentage of packetloss.
|
| This actually makes me wonder about whether there's a command
| that'll let me see short summaries of what every file under
| /usr/bin is, in the form of a list. Definitely wasn't aware of
| mtr as an average web developer up until now.
| lambdaba wrote:
| _apropos -s 1 ._ will list a short description from the
| manpages (might have to run _mandb_ first)
| ksec wrote:
| On the subject of Lease Time.
|
| My router is currently showing a lease time of 3 Min. I think
| most router tends to renew their IP at 50% of ISP's lease time
| ( in this case 6 min )
|
| What are the purpose of these ridiculously low lease time? I
| remember in the old days they tend to go for 48 hours if not
| longer.
| igetspam wrote:
| To get you to pay more money for a static IP.
| ksec wrote:
| Seems Reasonable, but I though most ISP dont want Home
| users to be using Static IPs.
|
| And apology for asking an off topic question. I guess that
| is what the downvotes are coming from.
| wernercd wrote:
| There's a limited number of IPs so most homes CANT use
| static... we already don't have enough IPs for the
| mountains of devices.
|
| But the other part is money... why give something away
| for free when you can make it a "feature" to pay for?
|
| Tons of other reasons in various articles...
|
| https://www.online-tech-tips.com/computer-tips/ott-
| explains-...
|
| https://superuser.com/questions/590391/why-do-isps-
| change-yo...
| eppp wrote:
| I work at an ISP and setup both static and dhcp services.
| Statics take far more work and management than dhcp,
| ignoring the scarcity problem. We make you pay more
| because you are requesting something that requires both
| documentation and management on a home connection.
|
| Id be glad to give them away for free but it is all
| downside for us and over 99% of residential customers
| dont want one to start with.
|
| I think we have 3 residential customers out of 1500 that
| have statics.
| runjake wrote:
| This is the correct answer. Although typically leases will
| attempt a renewal halfway through the lease time, so it would
| be a 48 hour lease.
|
| As OP said, mtr will tell you where in the line it's happening.
| throw0101a wrote:
| Actually it seems that it is not renegotiating everyday: it is
| expiring and re-requesting.
|
| The way DHCP 'should' work is that when a client is part-way
| through the lease it should try to renew the IP it already has:
|
| *
| https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Pro...
|
| * https://tools.ietf.org/html/rfc2131#section-4.4.5
|
| This allows the client to (hopefully) keep extending the IP it
| has so that a re-IP does not cause current connections to drop.
| If the modem is not doing this (can the OP log into it in
| someway to see logs?), then it is acting as a 'non-ideal' DHCP
| client.
|
| Until this is sorted out, try rebooting the modem an an 'odd'
| hour that will not disrupt you during the day. This is no
| guarantee though: the DHCP server may remember the old/current
| DHCP lease and simply re-issue it with the same expiration
| time.
|
| I'm on DSL/PPPoE, so this may not apply, but: my Asus router
| has a setting that allows it to automatically reboot. I do this
| at ~04h00 to get a new IP every day so help with privacy
| concerns. I generally surf with cookies disabled, so these two
| things help with the low-hanging fruit of simple tracking
| techniques. (My DSL modem is bridged.)
| dayjah wrote:
| I had this exact issue in 2008 in SF on Comcast Business.
|
| The lease would be dropped and renegotiated every few hours,
| we could notice it because our SSH tunnels would get torn
| down.
|
| What was annoying was that the business plan had a static IP
| associated with it, presumably managed by their DHCP setup.
|
| It took weeks to convince Comcast the issue wasn't in our
| building, and moments for them to fix once they "got it".
| patneedham wrote:
| What piece of evidence or logs finally convinced Comcast
| that the issue was on their side?
| dayjah wrote:
| Honestly my memory is not that good! I remember a few
| tech visits as they replaced modems, etc, and I
| eventually got to some "3rd level support person" that
| said something akin to "oh, that issue again".
| midasuni wrote:
| Did you try saying shibboleet?
|
| https://xkcd.com/806/
| oxfeed65261 wrote:
| c.f. Judges 12:5-6
| (https://www.bible.com/bible/114/JDG.12.5-6.NKJV):
|
| > The Gileadites seized the fords of the Jordan before
| the Ephraimites arrived. And when any Ephraimite who
| escaped said, "Let me cross over," the men of Gilead
| would say to him, "Are you an Ephraimite?" If he said,
| "No," then they would say to him, "Then say,
| 'Shibboleth'!" And he would say, "Sibboleth," for he
| could not pronounce it right. Then they would take him
| and kill him at the fords of the Jordan. There fell at
| that time forty-two thousand Ephraimites.
| landemva wrote:
| I saw this daily drop on several small biz Comcast setups.
| I recall I found it while looking through all the settings
| on the router, though I do recall having to call Comcast
| and they set something so it never happened again. It was
| the Comcast device with built in wifi. Hardwired didn't
| glitch, just wifi.
| mikewarot wrote:
| 1. Unplug your Router at some other time, for at least 5 minutes,
| long enough for your ISP to notice it's absence and give you a
| different IP address. If your 3:40 PM changes, it's the 24 hour
| expiration of your external IP.
|
| 2. Do a ping 8.8.8.8 from your Linux machine (Raspberry Pi) or
| ping -t 8.8.8.8 from windows, and watch what happens at 3:40 PM
|
| 3. As others have said, turn off uPnP
| Forbo wrote:
| This assumes that the ISP has a short lived DHCP lease. Comcast
| Business once tried to charge me to roll my DHCP IP from them.
| They told me I would have to disconnect my equipment for three
| weeks for the lease to expire. I told them to go fuck
| themselves, got a minicipal fiber connection, and never looked
| back.
| _underfl0w_ wrote:
| Must be nice! I wonder if OP even has the ability to switch
| ISPs (here in Texas, limited options)
| Triv888 wrote:
| With Comcast, if I spoof my router's MAC address, I get a new
| IP instantly... otherwise it is basically static (residential
| service).
| joshspankit wrote:
| A) There are a lot of potential hiccups with trying to get a
| new IP:
|
| - Some ISPs assign statically (odd, but true) meaning you will
| always get the same public IP
|
| - The DHCP lease time is different for many ISPs: 5min to
| weeks, meaning you'd have to be offline for at least that long
| in order to be assigned a new IP when connecting
|
| - Some ISPs lease it to the modem and not the router or
| anything internal (does not apply to what you said, but another
| tactic: changing the MAC address)
|
| B) OP asked how to investigate. _If_ getting a new IP dodges
| the issue and it doesn't happen again, then there's basically
| zero chance that the actual cause will be known
| scook wrote:
| Consumer ISPs don't always refresh IP addresses like that. I
| have had the same IP address on my home internet for years and
| was told that I would need to purchase a block of static IPs in
| order to recieve a new one.
| nicoffeine wrote:
| Make sure all your network devices / computers are synced via
| NTP, or at least accurate to the second.
|
| Hardwire the Pi to the network. Start a verbose traceroute and
| ping loop on a device on WiFi, as well as the Pi. Once it fails,
| observe the lights on your router/wifi device(s). Note time to
| the second of the start and finish of the outage, and the
| behavior of the lights. Check the results of your
| traceroutes/pings. Start digging through the logs of each network
| device.
|
| Also, you can never quite rule out power, even if the lights stay
| on. A power conditioning UPS is useful here.
| Siira wrote:
| Friendly advice, investigating this can only be worth the time it
| takes if you care about the learning or treat it as
| entertainment.
| bobowzki wrote:
| This could also be a power or electrical interference issue. I
| would start by logging the connection with ping every 1 sec or so
| to see if it's only 3:40pm.
| ayewo wrote:
| 1. Start the ping command at 3:39pm and leave it running until
| 3:41pm then make a note of whether packet losses start at 3:40pm.
| (E.g. "ping yahoo.com" on Unix or "ping -t yahoo.com" if on
| Windows).
|
| 2. If there are packet losses, then you have your answer: the
| issue is from your ISP.
|
| 3. If there are no packet losses, then you'll need to look closer
| at your network. Check to see if some hardware on your network
| might be performing a reboot at the 3:40pm mark.
| scotty79 wrote:
| It was easy way of dealing with router hanging up due to
| accumulated problems used by amateur internet providers. Just
| disconnect it from power once a day.
|
| You can do that with cheap socket timer.
|
| Not sure why would anyone set it to the middle of the day. Maybe
| error in setting times or clock or it was set intentionally so
| that you can service it at normal hours if it doesn't come back
| on.
|
| The problem is you can put in 'off' time and 'on' time but they
| have to be at least 1 minute apart.
| kratom_sandwich wrote:
| Are you familiar with the "Reply all" podcast? They have a
| "recurring segment, called 'Super Tech Support' [in] which [...]
| the Reply All team [...] takes on odd or especially complex tech
| support issues that the listeners or friends of the hosts have
| encountered." Not sure if your situation qualifies, though.
|
| [1] https://en.wikipedia.org/wiki/Reply_All_(podcast)
| davidro wrote:
| Change your DNS servers.. I use openDNS, but there are lots of
| other choices. If the Pi isn't in use set it up as a Pi-hole (DNS
| server / ad blocker), so you're not use your isp provided router
| for DNS.
| netsharc wrote:
| DNS probably has nothing to do with disconnects, this kind of
| random suggestion unrelated to the problem always makes me
| think of the Futurama Robot Judge:
| https://www.youtube.com/watch?v=Jqn8HB2w2Fs (skip to 0:15 for
| the punchline)
|
| Or maybe it is related, in which case I'll eat at a hat.
| mackatsol wrote:
| I've had outages that were due to my ISP's DNS service going
| down... one of the reasons I started using OpenDNS.
|
| I need to watch more Futurama. That was great!
| technick wrote:
| Are you using Spectrum / Charter by chance?
| raullen wrote:
| Mine dies for 10min
| pxeboot wrote:
| I had a connection through a small municipal ISP until moving
| recently. My connection would drop for several seconds at exactly
| 23:59 UTC every day. Never was able to figure it out.
| oger wrote:
| "My internet" is a bit vague - so I am making some assumptions
| here. Scenario (A) could be that your WiFi dies at a specific
| point in time. You might then want to look at some source of
| electromagnetic interference (like a motor starting while
| creating sparks). Scenario (B) could be that your internet
| service provider is cutting your connection and provides a new IP
| address - which is common for many xDSL providers. You want to
| check if the external IP address of your router changes. You may
| also find some log files in your router that may give you more
| information. Some routers allow you to select the time when the
| router preemptively disconnects at a certain time in order to
| avoid the disconnect from the ISP at an arbitrary moment. You may
| want change this setting or to talk to your ISP and try to
| convince him to not cut the connection during the day but rather
| during the night. Scenario (C) could be a device on your local
| network creating interference. Your tools of choice will be
| tcpdump and WireShark to locate the culprit on your LAN. Enjoy
| your debugging and good luck!
| rem1313 wrote:
| What channels do you use on wifi? If you you use DFS channels on
| 5GHz it could be a radar issue that forces your router to switch
| channels. I have it as well, but it happens at night so I'm not
| terribly concerned about it (my router sends me notification
| thats how I know).
|
| Edit: https://en.wikipedia.org/wiki/Dynamic_frequency_selection
| qwertox wrote:
| The devices are staying connected, so I doubt that this could
| be the source of the problem.
| wruza wrote:
| Your ISP does that. Apart from IP rotation theory, I heard that
| some ISP billing software requires a session reset to flush
| network statistics to a billing database, because it is
| accumulated in RAM. They have to do that to block/divert clients
| whose account reaches a limit, because you don't normally upload
| payment info to your firewall/proxy and only check it for new
| sessions. (I'm not an ISP guy and this may simply be an urban
| legend from 90's)
|
| My experience partially confirms that. I had an ISP who would
| redirect every syn packet on 80/443 to internal "low money" site
| in the night, but I had to reset my router after sending them
| money, cause otherwise that crippled session got stuck at their
| hardware until next autoreset.
|
| 1 minute may be a technical pppoe cleanup/reconnect timeout. Some
| shitty ISPs reset this timeout even for unsuccesful attempts, and
| this deadlock can last for half an hour until e.g. a router
| decides to back off for a while. Could be cured by turning it off
| for 3-5 minutes to cool off the ISP side. It's rare these days.
| grogenaut wrote:
| I will point out to all the people surprised at the time lining
| up that if the issue is a timer then this is likely very common.
| There are only 1440 minutes in a day, and waking hours are half
| that brinignrh it very close to the birthday paradox (double).
| https://en.m.wikipedia.org/wiki/Birthday_problem.
|
| If you consider 4 time zones in the us it's actually more common
| than birthdays since you'd divide by four again and people would
| suspect both a company wide tx synced issue and a per tx issue.
|
| With 23 people about 1/3rd of the people commenting at this point
| we get a chance of 2 people colliding as:
|
| Full day: 16% 12 Hour: 29% Across time zones: 79%
| mrkramer wrote:
| This is most probably because you have dynamic IP address and
| your router resets at the same time every day to fetch new IP
| address.
| tgeorge wrote:
| I would check out DSLReports and ask them there.
| http://www.dslreports.com/forums/all
|
| Chances are they experienced it there too. But I had an issue
| like that with Cablevision at 3-4am when they would push out
| firmware updates to the modem.
| drewpc wrote:
| I'm actually surprised by all of the comments. The community
| jumped right into solving OP's problem and has largely ignored
| the OP's original question of "how could I begin investigating
| this?" Another variation of this question could be "how do I
| troubleshoot complex network issues?"
|
| After 20 years of network/system/software engineering across a
| wide variety of network sizes and levels of complexity, I teach
| people the following method to troubleshoot complex network
| issues:
|
| 1. Write down the symptoms that you're seeing. How do you _know_
| something is wrong? What do you see happening?
|
| 2. Draw a diagram that includes all of the components and nodes
| involved. (this is hard)
|
| 3. Develop some hypotheses that could be worth testing. (this is
| hard and highly variable based on knowledge/experience)
|
| 4. Establish a "test plan" that allows you to prove/disprove the
| hypotheses while making _minimal_ changes to the system. Start
| from one source device and work your way out to the farthest
| component you identified in your diagram. Start at the lowest OSI
| layer and work your way up.
|
| 5. Methodically test components, step by step, along the diagram.
|
| 6. As you test, record your results. Add new hypothesis to the
| list as you gather more information but don't start testing them
| right away! You can develop a new test plan after you finish the
| first one that proves/disproves your new hypotheses.
|
| 7. Repeat all steps, adding new information, until you find a
| solution.
|
| I know this seems like a lot of steps when you're just
| troubleshooting a WiFi issue at home--it may be overkill.
| However, this framework applies to that scenario or when you're
| diagnosing any complex network issue. You'll learn more about the
| systems, protocols, and devices that truly make up the Internet
| than you could ever imagine. Through repetition and experience,
| these steps will get easier and some of them can happen quickly
| and in your head.
|
| To help you get started, here's some info for steps 1, 2, and 3:
|
| 1. From your post: "3:40pm every day my wifi loses internet
| access. My devices remain connected to the network, but all
| traffic dies. Almost exactly 1 minute later everything is
| resumed"
|
| 2. Start your diagram off as an "equipment string diagram". This
| will include all physical devices between you and the Internet.
| Along the way, you may need to modify the equipment string
| diagram to include "virtual" devices, network segments, various
| protocols/servers, etc. Your diagram should include at least the
| following items: - Your laptop/desktop. If it's
| happening to all devices, then pick one. Identify your IP and
| MAC addresses - The WiFi access point that device is
| connected to. Identify the IP and MAC addresses - Any
| switches, firewalls, modems, etc that connect from your WiFi
| access point to your Internet Service Provider (ISP) and their IP
| and MAC addresses. - The "next hop" from your modem into
| the ISP's network. You can use a cloud to represent the ISP's
| network that you don't know/understand, but always identify the
| IP address of the device that your modem first reaches. If you
| can find the MAC address (or other OSI Layer 2 address) as well,
| even better.
|
| That's the equipment string between you and "The Internet". For
| now, you can ignore the complexity inside the ISP's network and
| beyond. You might have to add more of that later, but start
| small.
|
| We know there are other components involved in making the
| Internet work that introduce complexity and can cause issues
| along the way. Let's list them on your diagram and identify what
| servers are used and where they might be located.
| - DHCP (local to your network and also between your modem and
| ISP) - DNS (could be local to your network and often is a
| third party service either run by your ISP or not) -
| Encryption (VPNs, SSL certificates, network device clock
| settings, etc) - IP routing (what devices do IP routing?
| Hint: all devices that operate at Layer 3, using IP, do IP
| routing--including your workstations)
|
| 3. Some hypotheses (some were identified in the comments):
| - Is there a device in the equipment string that is rebooting
| every day? - Is DNS intermittently failing? - Is DHCP
| releasing/renewing your IP address assignment? This could be
| from your device -> local DHCP server OR your modem -> ISP DHCP
| server - Is there an upstream connectivity issue with your
| ISP? - Is your WiFi access point losing connectivity?
| tacon wrote:
| The Universal Troubleshooting Process has been a web site since
| the mid-90s:
|
| http://troubleshooters.com/tuni.htm
| drewpc wrote:
| Thanks for sharing!! I've never seen this before.
| krona wrote:
| Reminds me of this news article: Old TV caused village broadband
| outages for 18 months https://www.bbc.co.uk/news/uk-
| wales-54239180
| to11mtm wrote:
| Oy! You got a license for that broadband jammer mate?
| andreasha wrote:
| Maybe the router is using DFS channels and some radar station
| takes a reading at that time every day and forces your router to
| change channel on its 5GHz network.
| tdiff wrote:
| I am using LTE internet via Huawei 3372 and it stops for about a
| minute or two exactly 6 hours after starting the modem (of course
| during some important call). After it, existing connections
| continue to work. I'm curious to know what might be causing this.
| tyingq wrote:
| At 3:39p, unplug your router and leave it unplugged for an hour,
| then plug it back in. If the outage then moves to 4:40p every
| day, it's a 24 hour IP address lease expiring.
| spuz wrote:
| Are you talking about IP leases from the router to the local
| network or IP leases from the ISP to the router?
| mvolfik wrote:
| likely router -> ISP - if it was the devices, they could show
| up as not being connected to the network. also weird that all
| devices' leases would expire at the same time
| jamescun wrote:
| Sounds very regular, may be worth contacting your ISP to see if
| that is their maintainence period or any other regular operation
| they may perform.
|
| I am with a broadband provider in the UK called Zen, at 23:15
| every Sunday our PPPoE session is terminated, and it takes a
| couple of minutes before it successfully resumes. Occasionally it
| will happen mid-week, however still at 23:15. At one point I
| suspected the provided FRTIZBox router, however the problem
| persisted once we moved to an MT992 modem and a Unifi USG.
| sgt101 wrote:
| What type of connection are you on? Is it DSL or fibre. If it's
| copper then my guess is that there is a device (like a heating
| pump) that's on a timer with a big switch thats creating a pulse
| of radio noise that's then echoing up and down the copper and
| pushing the session out of bounds. At that point the far router
| (in the dsl box on the road) will try and resync the connection.
| samradelie wrote:
| Probably not your issue: Internet: Old TV caused village
| broadband outages for 18 months https://www.bbc.com/news/uk-
| wales-54239180
| fersarr wrote:
| I was thinking of this too.
| merpnderp wrote:
| The sun was hitting my cable line at the same time every day
| causing my internet to go out, my router to reboot and the line
| power to be automatically increased. I finally called out a tech
| who fixed some old splitters and now the strength isn't just
| barely marginal enough that the sun would cause a drop.
| MrStonedOne wrote:
| Hack at the problem until its reduced to its purest form.
|
| > My devices remain connected to the network, but all traffic
| dies.
|
| Can the devices send packets within the network, but not the
| internet? Use ping to double check. if no, do you have any wired
| devices to confirm rather or not its wireless interference vs the
| router doing some sort of maintenance task.
|
| Does this impact all protocols? tcp/udp/imcp. I've seen random
| network hiccups only impact tcp before.
|
| ping tests imcp, dns (nslookup on windows/host on linux) tests
| udp (and can also test tcp) http tests udp and tcp, depending on
| browser and service. curl can let you confirm the test is going
| over tcp.
|
| MTR is likely your final solution for investigating this. It is
| like a traceroute that rapid fires out to get second by second
| details about all the hops in a network path. The types of errors
| you get can also tell you why.
|
| If it ends up being tcp only and internet based, things get
| harder, some mtr clients support using tcp instead of imcp to
| find hops where tcp breaks, but your isp routers might also
| refused to reply to such packets directly.
|
| Finally, watching the lights on the router and modem (if
| seperate) can be illuminating. First, get a feel for normal light
| operation, normal activity blink speed, etc, then starting a few
| minutes before the event normally happens, just observe the
| lights for changes until the event ends while also using your
| phone to know when the event has started and ended.
|
| On that note, look up how to access web consoles on the router
| (and modem if seperate). They may have event logs that tell you
| if anything is happening, like ip renewals, or if they are
| getting commands from the isp to do things.
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