Introduce a `--ttl` flag to allow users to set the IPv4 TTL or IPv6 hop limit, providing control over packet lifespan and helping diagnose network topology issues.
Apply the negotiated DSCP value to the UDP socket after a successful session open and clear it before closing to support network-level quality of service. This change adds platform-specific socket option handling for IPv4 TOS and IPv6 Traffic Class.
Verify that the client correctly handles custom packet lengths and server fill negotiation to ensure protocol compliance and support for larger MTUs. Add validation to reject empty server fill strings during configuration.
Nils Andreas Svee