Intermittent timeouts when resolving specific domains


#1

I posted about this back in January, but that post was mistakenly flagged as spam and subsequently removed. How a genuine support query can be classified as spam is beyond me, but I am not here to quibble over semantics and community guidelines.

Understandably, I am hesitant to repost the same issue lest it legitimately qualify as spam this time around. However, I have little choice in the matter. This forum is the only official support avenue for issues with 1.1.1.1, and I still have an unresolved issue that is interrupting my workflow.

There is a particular* web site that will at times fail to resolve. Both 1.1.1.1 and 1.0.0.1 timeout while resolving the domain. Using another DNS server works, and I can manually input the IP address into the browser to access the site.

(* I am omitting the domain name intentionally, in the event that its inclusion in my first post was somehow seen as advertising. If requested, I will provide the domain in question.)

What is peculiar is that nearly all other domains I use on a regular basis will continue to resolve normally during this time. And if I try the problem domain at another time or on another day, it might end up resolving properly. Lastly, I have yet to find any other domains that behave in this manner.

I do appreciate your time and help in this matter, as I would very much prefer to continue using CloudFlare’s DNS.

https://1.1.1.1/help/#eyJpc0NmIjoiWWVzIiwiaXNEb3QiOiJObyIsImlzRG9oIjoiTm8iLCJyZXNvbHZlcklwLTEuMS4xLjEiOiJZZXMiLCJyZXNvbHZlcklwLTEuMC4wLjEiOiJZZXMiLCJyZXNvbHZlcklwLTI2MDY6NDcwMDo0NzAwOjoxMTExIjoiTm8iLCJyZXNvbHZlcklwLTI2MDY6NDcwMDo0NzAwOjoxMDAxIjoiTm8iLCJkYXRhY2VudGVyTG9jYXRpb24iOiJTRUEiLCJpc3BOYW1lIjoiQ2xvdWRmbGFyZSIsImlzcEFzbiI6IjEzMzM1In0=


#2

In general, since the resolver works for most day-to-day operations then it’s likely something with the domain’s own DNS setup. Feel free to post it here.


#3

The domain is lsr.di.unimi.it which is a CNAME for sliver.docenti.di.unimi.it. When the timeouts happen, they occur for both the CNAME and A records.


#4

I am also experiencing the same issue. The domain is https://www.momomesh.tv/ When I ask 1.1.1.1 or 1.0.0.1 to resolve the host IP which is 102.165.33.6 it never resolves it as of March 3.


#5

After posting in now resolved for host [https://www.momomesh.tv


#6

Please correct me if I am wrong but wasnt that the host, respectively the DNS issue, we were discussing a while ago?


#7

You are correct, @sandro. I recall you helping before in the prior thread before it was removed. Unfortunately, we were not able to narrow down the problem.

It could very well be as @Judge suggests, where the problem is on the domain’s side and not Cloudflare’s. However, I am curious where the disconnect is, as Google’s resolver and my ISP’s resolver do not experience the same issue. Also, again this is only intermittent. Cloudflare’s resolver does work with the domain at times.

Perhaps there is an issue with load-balancing, where there is one errant server in a larger pool. If I am unlucky, I get the bad server that cannot service the request. I will readily admit I do not know the technology well enough to be able to point fingers anywhere, but my instincts say that the glitch is on Cloudflare’s side.


#8

http://dnsviz.net/d/lsr.di.unimi.it/dnssec/

Looks like one of the domain’s DNS servers can’t be reached over UDP. 1^4 is less fault-tolerant, so I would recommend 1.1.1.1 primary then 8.8.8.8 as the secondary/fallback DNS server.


No resolution for www.momomesh.tv
#9

Sounds like I will need to track down someone on the domain’s side and pass along the information.

In the meantime, I have made the recommended configuration change. Thanks for your help.