Static Outbound IPs only works for outbound connections. It doesn't do both outbound and inbound. So yes, if one of the services is meant to accept data from another service, then that won't work.

I enabled static IP for a service external to the application but I did not change the way of communicating between internal services, therefore with URLs, and they can no longer communicate

Can you please provide some error messages if you are still experiencing this issue?

Apart from the TimeOut I don't have any explicit error. But I can give a little more context via this example:

I have a service A with an url, let's say https://service-a.com

I have a service B with an url, let's say https://service-b.com

Both services are on railway

Without activating the "Static Outbound IPs" option, service A and B manage to communicate with each other without problems via their respective URLs.

If I activate the "Static Outbound IPs" option on service A, service B refuses the communication of service A, via the same URLs

This example reflects exactly the behavior we have

Tell me if it's clearer or if I can provide you with more information

Technical informations :
Our gateway service use mercuriusGateway
Our microservices are builds with NestFactory.create<NestFastifyApplication>(

AppModule,

new FastifyAdapter()

)

Any reason you aren't using the private network here?

Hi!
We are trying to use private networks, but our application (NestJS + Nixpack) crashes during the build when we provide private URLs to access our microservices.
Have you encountered this issue before?
Do you use "service-a.railway.internal" directly or "http://service-a.railway.internal" (with protocol)
?

The private network is not available during build, please do whatever you need to do with the private network during runtime before starting your application.

During runtime you would use http://[private domain]:[application port]/

Thank you, we'll try that.

We'll get back to you if we need more information.