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Having DNS reachability issues to dns server running on Cloudflare. It is reachable but from only 1 of the 3 internet uplinks we use. I suspect they may be blocking something that impacts our reachabilty and our customers access to some websites. How can you contact Cloudflare to verify if you are blocked and how to get unblocked if you are?

162.251.182.123 is one of the unreachable ip(It does respond to ping from certain source addresses)

What do you mean by DNS server running on Cloudflare? Like 1.1.1.1?

Actually this. Which may just be a Cloudflare customer ip.

Yeah, those are Cloudflare IPs. How are you checking just with ping? I might be worth checking with you ISPs given that one uplink works.

We are an isp. I have tickets with the backbone providers and so far I may have convinced telia that they have a route issue. Cogent on the other hand is trying to send me to Cloudflare. I can ping it from cogents looking glass but not from our interface ip provided by them for our connection. I can also ping it from telia looking glass but not our telia ip.

I can reach it from hurricane electric fine.

Forgot to mention I am sourcing my pings from the upstream provider ip space.

Yeah, that does seem like an upstream thing if it doesn’t work from your interface IP, but with their looking glass.

It probably is. I can ping .1 from all three providers interface ip also.

Open tickets with your upstreams with all this info. If they say it is not them, then ask for evidence why.

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Have you tried emailing Cloudflare at [email protected] or they have a portal https://www.cloudflare.com/partners/peering-portal/

Obviously the more details the better.

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I have that is what i am talking about. They say they can get to Cloudflare network and contact Cloudflare who won’t answer me at all.

This is good info thanks. I will try them. I will document specifically source and destination ips etc.

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