ISP resolver intercepting my DNS

Website, Application, Performance DNS & Network
1

And now I’m even more confused. These are the ping results from two different machines:

ping picperf.dev
PING warning-security.landing.telstra.com (203.50.142.140): 56 data bytes
64 bytes from 203.50.142.140: icmp_seq=0 ttl=55 time=5.673 ms
64 bytes from 203.50.142.140: icmp_seq=1 ttl=55 time=11.497 ms

ping picperf.dev
PING picperf.dev (172.67.223.180) 56(84) bytes of data.
64 bytes from 172.67.223.180 (172.67.223.180): icmp_seq=1 ttl=50 time=185 ms
64 bytes from 172.67.223.180 (172.67.223.180): icmp_seq=2 ttl=50

Why would these be different?

2

@alex77 I have moved this to its own topic as it appears to be a distinct issue that is separate from your question about ACM and Cloudflare workers.

3

They are different hostnames? The first is likely not a host under your control, did you mean to use a different hostname?

They resolve to the same IPs you got in your results for me.

dig warning-security.landing.telstra.com +short
203.50.148.12

dig picperf.dev +short
104.21.80.145
172.67.223.180
4

Ah @epic.network perhaps he is trying to say when visitors got to picperf.dev they are presented with the warning-security.landing.telstra.com page? In that case you should contact telstra to determine why.

Just a guess. :person_shrugging:

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5

That’s what it sounds like to me, too.

6

Thanks for chiming in, guys. This report came from someone who hit the domain from two different machines. The at other domain was not causing a different page to render. It was only throwing various SSL-related errors.

It was also when I had multiple different SSL certificates set up for it. I’ve since removed them and generated a single new one.

There’s some more context on this issue if you’d like to look.

7

Yeah I chimed in on the GitHub issue. It is likely a web filtering product on their router. They should talk to their ISP. The page being rendered is not yours… it is a block / filter page from the DNS entry.

1 Like
8

Thanks! After a lot of trial & error, I confirmed that you’re right – looks like an issue with their network or firewall. Specifically, related to the .dev domain I was using. After I wired up picperf.io to my worker, all of these errors went away. It seems like some networks still don’t trust .dev domains.

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9

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