Running TCP DNS server?

A post was split to a new topic: DNS over TCP works, but UDP doesn’t

Was able to deploy over TCP/853. But no connections seems to reach it.

Also tried using fly-global-services as hostname, then even TCP/53 stops working with [error] Error 2000: problem connecting to app instance.

Not ready yet?

@thomas ^ we have open requests for 853 and 7777.

Hey! 853/tcp should work now (you don’t need fly-global-services for this! You only need that for UDP, so that our XDP code doesn’t mess with the UDP DNS that your VM already generates).

7777/tcp turns out to be slightly tricky for reasons I am too embarassed to report here but will explain once we’ve fixed it, which is the next thing on my docket.

Sorry for the delay on the first port; I added it to our API, but it was waiting on a fleet deploy to actually work. It is very silly that we have to do big deploys to add ports, and that too is something we are working on fixing.


Hi, 853/tcp is still not working. Tried a redeployment a few mins ago.

Unable to connect to it, getting Connection refused error.

Edit (3h later): It is working now! Thanks!

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Is this port 853 not available in all regions?

Port are mapped like so:

TCP      443 => 8080 []  
TCP      853 => 10000 []

I’m having trouble with deploying to all regions and with autoscaling:

Hi @Rowan_Hamilton , it should be, per

Can you check Troubleshooting your Deployment to see if your port-related config in the fly.toml is per this.

You can also look in the logs to see if you find anything that looks like an error, i.e., flyctl logs.