Stale CF-COnnecting-IP Header Part 2

Website, Application, Performance DNS & Network
1

A little while ago, I posted about this issue:

Today, with the help of a more knowledgeable friend, we tried to dig deep into this issue, testing across different servers and configurations.

What we found is this:

  • There are several different Cloudflare IPs that respond to the DNS request to our domain
  • When the Cloudflare IP is 172.67.175.14, this stale header issue occurs
  • On other Cloudflare IPs, the CF-Connecting-IP header is updated immediately after resetting the client connection

So, this is definitely an issue on the CF side of things.

1 Like
2

I’m wondering if it could be something ISP specific as I cannot reproduce any issue here, nor even imagine how it would happen.

I test a bit as I have multiple external IPs and can control which is used, it is always up to date when I make a switch. Even just flipping between wifi networks is sufficient.

Can you reproduce on sites that are not hosted on Cloudflare?

3

Tested in “gray cloud” mode, the REMOTE_ADDR and X_FORWARDED_FOR headers update immediately

7

You are referring to inbound connections here, correct?

I’d still say it is unlikely to be Cloudflare related, however if you can reproduce the issue it is best to open a support ticket and have them check out any potential issues with that particular address.

8

That’s right, my server is seeing stale IP client addresses from a CF server…

Let me see about opening a ticket, last tie I tried I was asked to post here…

9

Support told you to post here? Thats not exactly what they should do.

10

No, I mean, the process to find where to open a ticket on the website, encourages people to come and post here first. took a bit of digging t find the “open ticket” button, but it’s done :slight_smile:

11

Did you got any clarification from support?

12

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