Getting connection errors on IPv4 connections (IPv6 works)

For some reason I cannot access one of our apps via IPv4.

$ curl -4v
*   Trying a.b.c.d:443...
* Connected to (a.b.c.d) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
*  CAfile: /etc/ssl/cert.pem
*  CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to
* Closing connection 0
curl: (35) LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to

Here is the relevant snippet from fly.toml.

  internal_port = 8080
  processes = ["app"]
  protocol = "tcp"

    handlers = ["http"]
    port = 80

    handlers = ["tls", "http"]
    port = 443

Tried to access it from multiple sites with different internet connections and ISPs, but no luck.

The affected app is “…-production-app”.

Does anybody have any ideas what could be the problem here?

Sorry for the trouble. Is this a newly launched app?

Not really. The app has been created some days ago. I would get you more details, but when clicking the “Activity” menu item in the dashboard the server returns a 500 error.

That’s really weird. I don’t think there’s any different handling of IPv4 than IPv6 in our environment.

Will you visit and tell us what you get for FLY_REGION?

Oh! I found the error, it seems the IPv4 didn’t get attached to your app properly at deploy time. It’s fixed now, will you give it another try?

Sorry for the late answer … it’s working now. Thanks a lot!