Strongly suspect this device doesn't have a RTC...
TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
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Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#32Update: According to ktta ( https://news.ycombinator.com/item?id=15912467 ), there is mistake in my calculation too. "138KB * 24 * 3600 / 5" should be 2.3287GB per day. And it's 2.3287GB * 30 per month. Update 2: "For comparison, a 5-minute check would be considered a pretty aggressive checking interval, and would only consume 1,37 MB per month. Instead, TP-Link goes through the same amount of data in just 82 minutes…
Also I think it is 138 B, not kilobytes since that would be 2.3GB/day.
Whoops. Made it to the front page of HN with so many mistakes.
EDIT:
Since there seems to be interest in this let's do the test:
5 DNS requests + 1 NTP update according to the article (seems weird that it would resolve all the the NTP servers, but lets roll with it)
DNS: dig (mean for request is 43.8 B and reply is 84.6 B)
NTP: busybox_NTPD -n -q -p time.nist.gov
---------------------
Egress:
Single DNS request : 20 (IP) + 8 (UDP) + 44 (DNS) = 72 B
NTP request (2 packets): 20 (IP) + 8 (UDP) + 48 (NTP client) = 76 B
Total egress: 72x6 + 76x2 = 584 B
----------------------
Ingress:
Single DNS reply: 20 (IP) + 8 (UDP) + 85 (DNS) = 113 B
NTP reply (2 packets): 20 (IP) + 8 (UDP) + 48 (NTP server) = 76 B
Total Ingress: 113x6 + 76x2 = 830 B
----------------------
The total bandwidth used according to my calc is 1414 B. So their number of 138 KB is actually 1.38 KB (which is 1380 B, and that's closer to my number. I rounded up if you look at my numbers)
So their number of 715 MB is actually right. Just an error with 138 KB -> 1.38 KB
Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#33Update: According to ktta ( https://news.ycombinator.com/item?id=15912467 ), there is mistake in my calculation too. "138KB * 24 * 3600 / 5" should be 2.3287GB per day. And it's 2.3287GB * 30 per month. Update 2: "For comparison, a 5-minute check would be considered a pretty aggressive checking interval, and would only consume 1,37 MB per month. Instead, TP-Link goes through the same amount of data in just 82 minutes…
There are 86,400 seconds in a day. 138KB x 86400/5 = 238640KB /day = ~2328 MB/day = 69,840 MB/month = 67 GB/month.
I'm going to go on a limb and say his 138KB is more like 1.38KB which would bring us closer to his 0.71 GB/month
Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#34Somewhat unrelated but if you are looking for a rock-solid router, check out Microtik. I've been through half a dozen routers over the years, with and without custom firmware, and having owned a Mikrotik Routerboard for the last year, it's the first one that just works 100% and never drops connections. Easy to set up if you know what you are doing and customizable if you want to dig in.
Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#35Update: According to ktta ( https://news.ycombinator.com/item?id=15912467 ), there is mistake in my calculation too. "138KB * 24 * 3600 / 5" should be 2.3287GB per day. And it's 2.3287GB * 30 per month. Update 2: "For comparison, a 5-minute check would be considered a pretty aggressive checking interval, and would only consume 1,37 MB per month. Instead, TP-Link goes through the same amount of data in just 82 minutes…
Basically, every 5 seconds:
(6 * (75 + 125)) + (90 + 90) == 1380
276 * 86400 == 23,846,400 -or- 1380 * (86400/5) == 23,846,400
23,846,400 * 30 == 715,392,000
Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#36Earlier quoted context omitted.
>So your convenience trumps the impact you’re causing to global infrastructure Honestly? Yes. Should I want TP-Link to fix it? Maybe. Should pressure be put on TP-Link to fix it? Yes. But not by consumers. It isn't the responsibility of a random consumer that has no idea what an NTP server even is to understand whether or not the TP-Link router is going the "right thing" for all sorts of use cases they've never even…
What's the point of the NTP pool providers making their concerns public when consumers like you, who apparently are aware of the issue and what it means, don't care because TP-Link makes a "good product"? Your attitude kind of reminds of the people that toss their cigarettes out their car window. When confronted they'll say something like "But my car doesn't have an ashtray, this is easier" or "But I don't want used…
Because I'll be more concerned if the NTP pool providers say "This is detrimental to our services" than if a random 3rd party blog (that has apparently not even checked their math) says I should worry about it.
Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#37Update: According to ktta ( https://news.ycombinator.com/item?id=15912467 ), there is mistake in my calculation too. "138KB * 24 * 3600 / 5" should be 2.3287GB per day. And it's 2.3287GB * 30 per month. Update 2: "For comparison, a 5-minute check would be considered a pretty aggressive checking interval, and would only consume 1,37 MB per month. Instead, TP-Link goes through the same amount of data in just 82 minutes…
Also I think it is 138 B, not kilobytes since that would be 2.3GB/day. Whoops. Made it to the front page of HN with so many mistakes. EDIT: Since there seems to be interest in this let's do the test: 5 DNS requests + 1 NTP update according to the article (seems weird that it would resolve all the the NTP servers, but lets roll with it) DNS: dig (mean for request is 43.8 B and reply is 84.6 B) NTP: busybox_NTPD -n -q…
[deleted]
Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#38I use a TP-Link travel router while on the road to get access for all of my devices in hotels that have device caps, and for my Android TV devices which don't gracefully handle hotel login prompts. I have to say that the convenience, ease of use, and reliability of the product far outweighs any concerns I have over ~715MB over the course of a month. It boots quickly once plugged in, it reliably handles 4-5 devices ut…
I've got a couple of MR-3020 "travel routers" myself, though I run OpenWRT on 'em. They're pretty decent little boxes and well worth the $15 or so that I paid for 'em.
I've got the successor, the TL-WR902AC
Looks like LEDE might support them, though when I purchased it, it did not. I might check that out.
Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#39PSA Anyone with commodity routers, repeaters, etc. please check out LEDE project https://lede-project.org . Check if your device has support here - https://lede-project.org/toh/start LEDE firmware is amazing. You will be able to do a lot more with your router and they have quick security fixes. The recent krack vulnerability was fixed within 2 days after the announcement.
I'm interested in installing a different firmware on my home router, but there are many offerings. Is there any reason you recommend LEDE over the others? (e.g. Tomato)
OpenWRT/LEDE firmware is nice. I think I first used it with the (original) WRT54G.
The future of the project is uncertain, however. They may or may not be around much longer.
Re: TP-Link firmware sends six DNS requests and one NTP query every 5 seconds
#40I discovered PC engines APU boards and now I do all my routers/network thingie with it and OpenBSD. I'm quite sure there are some nice GUI "ala pfSense" too, but I like my configuration files better.