Where to find the default DNS resolver configuration of a Reactive Spring Boot / WebFlux application? Is TCP fallback enabled?

We have multiple Reactive Spring Boot applications (WebFlux) running in Azure Container Apps. Since they run in Azure we can see some sporadic netty DNS resolver timeouts which we try to track down. We haven't seen them on premises. One hint is that this could be a UDP trunction problem and we should enable TCP fallback for the netty DNS resolver.

Now I would like to know two things:

1. Where to find the netty dns resolver default configuration? Is this in Spring, Reactor or the Reactor HTTP/TCP client? I want to check if TCP fallback is already enabled or not.
2. How to change this default to make it work for the whole JVM/application?

I tried to find it in the Github code repos but got lost.

Sources:

• netty DnsNameResolverTimeoutException
• Redisson using TCP fallback which is available but not enabled by default in the netty DNS resolver

Reactor Netty enables by default the TCP fallback. You can see the configuration here