Getting connection errors on IPv4 connections (IPv6 works)

1

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

$ curl -4v https://app.at.domain/
*   Trying a.b.c.d:443...
* Connected to host.at.domain (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 host.at.domain:443
* Closing connection 0
curl: (35) LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to host.at.domain:443

Here is the relevant snippet from fly.toml.

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

  [[services.ports]]
    handlers = ["http"]
    port = 80

  [[services.ports]]
    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?

2

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

3

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.

4

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

Will you visit debug.fly.dev and tell us what you get for FLY_REGION?

5

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?

6

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