Don't use strings!

[Bartolomeus-649]

Why use a string?

public class ServerPeerBinding
{
   /// <summary>IP address and port number on which the node server listens.</summary>
   [IPEndPointValidator]
   [Required]
   public string EndPoint { get; set; } = string.Empty;
    ...

In my opinion strings should be used for one and one thing only, and that is for containing text which only use is too be displayed to a human. Anything else should be stored in a suitable type.

In this particular case there is even a .NET class: IPEndPoint.