My web app behind Cloudflare cannot be accessed by IPv6 clients
I have a strange situation that I have never encountered before. Almost everything else works correctly except when a IPv6 client tries to connect. This happens to my entire domain (including its subdomain).
curl <mydomain> is fine but curl -6 <mydomain> would timeout after about 40s.
Could someone suggest something I can go on please? Thanks
13 Replies
IPv6 Compatability is on and I cannot disable it anyway
Could this be to do with what you're running on the domain?
@WTDawson9 thanks but I think it's unlikely. I only have one A record (IPv4) and as long as I connect with IPv4, everything is fine, the server respond within 1 second. What I meant is, my server definitely cannot know if a connection is from IPv4 or IPv6
Hmm, interesting
What is the error you get when you connect over an IPV6 IP?
@WTDawson9 it simply times out.
and it is not due to my computer as well because I tried with other URL like example.com and stackoverflow.com, everything works fine.
Hmm
What about port 80?
my domain has TLS enabled and port 80 should not accept requests from this domain but sure I will try:
Hmm
@Leo I have an EC2 instance with OpenVPN, I tried on either Remote Dekstop and OpenVPN, the request simply timed out but faster (within a few seconds).
Ah
The VPN may have issues
right, I can't ping them as well. the IP Cloudflare resolves to me is 2606:4700:3033::ac43:db2d
I just used it to test if it's my ISP issue or everyone's. Even without VPN I still have the issue (and the VPN cannot connect to my website too anyway).
Viettel in Vietnam. That's strange because my EC2 instance is AWS in Virginia and it has the issue too.
it returns HTML for you? that's strange indeed.
I am trying to connect from another EC2 instance. I forgot that the EC2 instance I was using (+ OpenVPN) was the same instance that serve the website. Still I don't think that should be an issue because the website is behind Cloudflare so my server cannot know that anyway.
This is the output for
curl from my other instance. Still failed 😦Cloudflare Community: My website cannot be connected to by IPv6 clients
Might be a result of: The unintended consequences of blocking IP addresses