NetDiag+
NetDiag+ 1.4: nine new tools, all on raw sockets, no jailbreak
1.3 was a toolkit. 1.4 is the release where it became the toolkit a network engineer would keep — nine tools that are usually only found on a laptop, running on an iPhone without root, a jailbreak or a companion app.
The nine
- MTR — continuous traceroute with per-hop loss and jitter. Probes run in parallel, so a cycle takes about one probe timeout rather than the sum of thirty; it survives navigating away and keeps its history.
- Path MTU discovery — ICMP Echo with the Don't-Fragment bit, not UDP guesswork. Why that matters, and what to do with the number.
- TLS Inspector — certificate chain, protocol, cipher, ALPN, probed in parallel.
- STUN / NAT type — what kind of NAT you are behind, which is the first question for anything peer-to-peer.
- Encrypted DNS — DoH and DoT reachability per provider, so you know whether the network is quietly blocking them.
- HTTP/3 (QUIC) — a real QUIC probe through NWConnection, not a URLSession that silently falls back to HTTP/2.
- IPv6 diagnostics — global address, real reachability, NAT64/DNS64 detection, tunnel interfaces classified as tunnels.
- Bonjour / mDNS — what is announcing itself on the local network.
- Site Reach — TCP/443 to a list of well-known sites, with detection of SNI-based blocking, which looks like a timeout to everything else.
Every tool has an info sheet explaining what it measures and what the result does not mean. The write-up of how these work without entitlements is on dev.to.
1.4.1 and 1.4.2
1.4.1 fixed a crash that several 1.3 users reported as "ping closes the app on the third packet": a write to a socket whose peer had already closed raised SIGPIPE, whose default on iOS terminates the process. The signal is now ignored process-wide and the failing call returns an error the tool already knows how to show.
1.4.2 hardened traceroute and MTR against an intermediate hop answering "unreachable" — they used to stop there as if it were the destination — fixed the speed-test download, and removed a false SNI-block verdict in Site Reach.
Download on the App StoreFree · 27 tools · one-time purchase removes ads · no subscription