G’day,

I’m on a 100/40Mbps HFC plan, and have an ongoing issue where the internet in general (browsing, file access, email, cloud hosted products, etc) will just grind to halt.

For example, I can be accessing our CMMS and suddenly a page load will take 30+ seconds to complete. Never times out, just takes forever. Or I’m using our accounting software which syncs remotely and saving an invoice or opening a purchase order will stall for a minute.

This behaviour goes on for maybe 5 minutes or so and then goes away again. It can occur once or twice in a 10 hour day at the office, or not at all, or sometimes half a dozen times in a one hour period.

  • Local network use is unaffected (for e.g. accessing SMB shares to a local server)
  • All PCs and laptops connected to the LAN are affected so its not PC-specific.
  • Ping is unaffected and hovers around 12ms to geographically close remote servers, with no packet loss or jitter.
  • Speedtests of any kind always return around 95/35Mbps at any time be it peak / off peak / when problem is occurring / when problem is not occurring
  • VOIP does not seem to be affected despite being on the same network and I can talk on the phone while the internet is otherwise wading its way through treacle.
  • Happens with my current ISP (Leaptel), but also happened the previous ISP (Aussie Broadband) who are 100% completely different companies and I believe use completely different peering/routing/backhaul/etc.
  • DNS seems irrelevant and occurs using either the ISP DNS, Cloudflare, Google, or Quad9
  • Some websites like Facebook and Google work, but other websites like Lemmy (any instance), Reddit, my CMMS, various wholesaler sites hosted both in AU and worldwide, are affected.

Are there any steps I can take to try and identify what causes this random delay? Its just enough to be really frustrating, especially when you’re trying to look up something while on the phone and have to be like “so yeah hows the wife? hows the kids? hows the…dog? … pet bird doing anything interesting?” as you wait for a damn page to load. I need fast internet so I dont need to make small talk dammit.

PCs are all on cat5e or cat6 (depending on when the cabling was run), to a Ubiquiti Dream Machine SE which is connected via cat6 to the NBN HFC modem.

  • bookmeat@lemmynsfw.comEnglish
    1·
    6 days ago

    Unplug everything from the router. If the router has a speed test built-in, use it and see the baseline performance. Start plugging stuff in and see when it starts going to shit.

  • SteveTech@programming.devEnglish
    1·
    6 days ago

    Some websites like Facebook and Google work, but other websites like Lemmy (any instance), Reddit, my CMMS, various wholesaler sites hosted both in AU and worldwide, are affected.

    I wonder if IPv4 is somehow wonky, but IPv6 is working fine? Since Facebook and Google definitely support IPv6, the others may not (although Reddit should too).

    You could try comparing ping -4 and ping -6 when it happens. That is if your network supports IPv6.

    If you do get any inconsistencies with ping, you could also try experimenting with traceroute/tracert, to see where the delay happens.

  • TauZero@mander.xyzEnglish
    1·
    6 days ago

    First thought was ISP intermittent packet loss, but

    Ping is unaffected
    no packet loss or jitter
    Speedtests of any kind always return when problem is occurring / when problem is not occurring

    Suggests otherwise. My second thought was DNS crashing, but

    DNS seems irrelevant

    You already got it covered.

    Some websites like Facebook and Google work
    VOIP does not seem to be affected

    Really weird situation! Try using wireshark to listen on the interface and observe what’s happening. Are packets going out but none returning? Are they returning with errors? Retransmissions? Are some destinations fine but others get no reply?

    Could you geographically locate the IPs that work vs. the IPs that don’t? My next suspicion is that there is some upstream backbone link that cuts out, so stuff with local CDNs like facebook continue to work, but a lemmy server on another continent is unreachable. Try traceroute.