[berbc]

Given formal semantics of your programming language and some time, I think you can use Agda to prove interesting properties about correct programs you write in that language. Semantics, the behaviour of objects such as sockets, can be encoded in types the theorem prover can understand. It can look like this for a basic imperative language: https://github.com/Twey/imp-agda/blob/master/IMP/Semantics/O.... You can then define the property you are interested in and get your proof by combining these types together.

This is often tedious but can be automated to some extent and has already led to significant achievements. See http://sel4.systems, a proven kernel, done with Isabelle, a tool similar to Agda.

Maybe you are looking for a language with a type system that will force you to write your program in a safe way regarding sockets and the like. This can also be achieved with static analysis, another way of automatically proving properties about programs. I do not know of any for distributed programs but it is probably possible. I would say this is still a research topic as such programs are still so hard to get right.