Continuous per-hop network probing (mtr) for Android.
MtrScope is a lightweight, native Android implementation of the classic
mtr (My Traceroute) tool.
It continuously probes every hop between your device and a target host,
re-live-updating loss % and latency so you can watch a network path degrade or
recover in real time — a familiar workflow if you are used to mtr on Linux.
Google Play — https://play.google.com/store/apps/details?id=com.paperclip.mtr
Or download the APK directly — https://github.com/saycc1982/mtr-scope/releases/latest
- MTR / PING trace — continuous live per-hop probing with real-time loss %, sent count, last / average latency, and per-hop sparklines & loss bars.
- Multi-tab parallel trace — trace several hosts at once (one tab each); a STOP stops all running tabs. Batch mode (several hosts separated by commas / newlines) opens a tab for each in a single tap.
- IP geolocation + ASN — every hop tagged with its country code and
autonomous system (e.g.
[HK AS9429 HKT]), toggled on/off via the ASN box. Reserved/private ranges are skipped (no public ASN). - rDNS (reverse DNS) — resolves the hostname of each hop; toggleable live
while tracing. IPv4 (
in-addr.arpa) and IPv6 (ip6.arpa) are both handled. - WHOIS — tap a hop (or a domain/IP in the header) to look up WHOIS for
IPs and eTLD domains. Replies are decoded UTF-8 first, so non-ASCII registry
data such as the Chinese registrant / registrar returned for
.cnand.com.cndomains reads correctly. - Health bar + trend chart — target-hop summary (
Loss / Avg / Jitter), tap for the time-series trend chart. - Visual route map — plots each public hop on an OpenStreetMap / Leaflet map and draws the great-circle route with red direction arrows, skipping private/internal hops and starting from your own public IP.
- Your public IP (v4 + v6) — shown in the header via a live external probe, cached and re-checked automatically when the route or network changes.
MOREtoolbox- Net Info — interface, IP stack (Dual-stack / v4 / v6), MTU, gateway, DNS servers.
- DNS Lookup — raw UDP A / AAAA / CNAME / NS / MX / TXT / PTR / WHOIS / ALL, with history; tap a returned host/IP to start an MTR or PING on it.
- TCP Port Scan — single / list / range / mixed port specs
(
443·80,443,8080·1-1024·80,443,1-1024), an IP family selector (IPv4 / IPv6 / IPv4 + IPv6, default IPv4, remembered) with each family's result shown separately. Before any IPv6 target is probed, the app fetches its own public IPv6 from an IPv6-only service — a host that publishes a AAAA record and no A record, so a reply proves IPv6 really works. If none comes back it reports "Your network does not support IPv6" and offers a one-tap switch to IPv4 rather than pretending every port is closed. Results also distinguish open / refused (host reached, port closed) / timed out (unreachable).
- History — search / compare / favourite / clear past traces, auto-saved after the first complete round (not only on STOP).
- Export & copy — copy the table as text / CSV / JSON, share, or export the
table as a PNG (QR code of the result included); a
☰diagnostic log. - Dark / light theme — 3-state (system / light / dark), switchable even while tracing; the active host is resumed automatically.
- Home widget — tap the widget to enter a host, then
▶ MTR/▶ PINGruns it straight away (each widget instance remembers its own host). ☰hamburger menu — Log, About and FAQ tucked away to keep the main UI clean.
Note on probing: raw ICMP is blocked on Android, so MtrScope shells out to the system
pingbinary with increasing TTLs (-t) to reveal each hop — the same techniquemtruses. Real devices return real mid-route routers.
| Empty start screen | History dialog |
|---|---|
 |
 |
Google Play (auto-updates, no sideload prompt): https://play.google.com/store/apps/details?id=com.paperclip.mtr
This repository is also the direct APK distribution channel for MtrScope — it carries no source code, and the single signed APK sits on the latest release:
- Download
mtrscope-v<version>.apk. - Open it on the device and allow the install when prompted (it is a sideload).
- The app needs no account, no ads and only the two network permissions it uses
(
INTERNET+ACCESS_NETWORK_STATE). It runs on Android 8.0 (API 26) or newer.
The same APK is mirrored on the author's own download server, so a release stays obtainable even if a CDN ever drops it — the exact URL for the current build is listed in that release's notes.
The Play listing and the GitHub APK carry the same build, so picking either one gets you the identical app; the Play route simply keeps itself updated.
- Type a hostname or IP in the input (e.g.
8.8.8.8,yam.com). - Tap MTR for a hop-by-hop trace, or PING to just watch the target's latency/loss over time.
- While tracing, watch the live table. Toggle rDNS / ASN to show or hide reverse names and geo tags.
- Tap 🗺 map to open the route map, 🕘 history for past traces, 🖒 top to pin to the top, and 📋 copy to copy the current table.
- Tap a hop to WHOIS it; long-press to copy that hop.
The following describes the design at a concept level. It is documentation, not buildable code — this public repository contains no source.
| Piece | What it does |
|---|---|
MtrEngine |
Orchestrates the continuous trace using the system ping binary with increasing TTLs. |
GeoLookup |
Resolves each hop to country / ASN via ip-api.com (public IPs only), with a disk cache and country-centroid fallback for the map. |
Whois / Psl |
WHOIS lookups including eTLD extraction (Public Suffix List). Port 43 replies are decoded UTF-8 first and fall back to Latin-1 only when strict UTF-8 yields a replacement character (measured: CNNIC answers in UTF-8, Verisign / APNIC / IANA are pure ASCII). |
DnsQuery |
Minimal raw UDP DNS resolver (A / AAAA / CNAME / MX / NS / TXT / PTR), random per-query id with reply matching and full bounds guarding. |
PortScan |
Concurrent TCP connect scanner with a family selector (IPv4 / IPv6 / both) that reports each family separately. |
NetInfo |
Active-interface report: transport, IP stack (via network capabilities), MTU, gateway, DNS servers. |
map.html |
A local Leaflet 1.9.4 page that draws the great-circle route, unwraps the antimeridian, and renders red direction arrows. |
HistoryStore |
Persists past traces for search / compare / favourite / clear. |
- Probes run sequentially (one TTL at a time) — concurrent probes inflate latency on real devices.
- The engine always passes
-t <ttl>for MTR mode, includingttl=1; without it the first probe reaches the target directly and hides every real hop. - Every start bumps an internal generation counter, so leftover replies from a previous target can never land in a fresh table.
- TCP Port Scan picks the family by explicit selection (not auto-fallback):
a literal IPv4 / IPv6 address is always probed as typed, and a hostname
follows the chosen family. Whether IPv6 is usable at all is decided only
by fetching the device's own public IPv6 from an IPv6-only service (AAAA
record, no A record). Nothing else on the system is trusted as proof:
NET_CAPABILITY_INET6(15 = IPv4, 16 = IPv6 — hidden constants, hence the magic numbers) is set for the pseudo/dummy IPv6 prefixes that IPv4-only cellular links hand out, so a v4-only phone can legitimately be labelled "dual-stack", and an echo service that also has an A record is reachable over v4 and answers with your IPv4 address. The capability flag is therefore shown in Network Info as a claim only ("IPv4 only — OS claims IPv6, but no IPv6 address is reachable"), never as proof. Each probe is still classified open / refused / timed out, and a refused result is deliberately not taken as proof of a dead stack, because a network that can fabricate an IPv6 prefix can fabricate the reset as well.
- Hops with private/internal IPs (
10.x,192.168.x, …) are skipped — they have no public geolocation. - The route origin is your device's own public IP (shown as
IP [CC ASnnn Name]), fetched best-effort with a short timeout so the map always opens quickly. - The path is a great circle (shortest arc on the globe), so e.g. Hong Kong → US renders across the Pacific, not a flat line across Asia.
A longer version lives in-app under ☰ → FAQ. Highlights:
- Why does WHOIS show accented garbage like
ä¸å½çµä¿¡? That was our bug, since fixed: WHOIS replies are decoded as UTF-8 first (with Latin-1 only as a fallback), and registries such as CNNIC (whois.cnnic.cn) really do return UTF-8 Chinese —chinatelecom.com.cnyieldsRegistrant: 中國電信集團公司. If a reply ever looks wrong again, the registry in question is the exception, and the raw bytes can be checked withprintf 'domain\r\n' | nc <whois-server> 43. - Why are some hops internal IPs? Those are your ISP's route-local addresses; they have no public geolocation and are skipped on the map.
- Why do some hops show
*? No reply for that TTL on this round (a router that silences the packet or plain loss) — the row still counts as sent. - What does
[HK AS9429]mean? Country code + the autonomous system (ISP) that owns that IP. - Why does the map route cross the Pacific? It draws the great-circle shortest path, not a flat straight line.
- Why does a TCP port scan of an IPv6 address say "Your network does not support IPv6"? The app tried to fetch this device's own public IPv6 from an IPv6-only service and got nothing, so no IPv6 packet can leave the device and an IPv6 scan could only ever time out. Use an IPv6-capable network or scan IPv4. A closed port shows as refused (the host was reached) while an unreachable one shows as timed out — those are not the same.
- Network Info says "Dual-stack (v4+v6)" but IPv6 does not work — why? Carrier IPv4-only links can hand out a pseudo IPv6 prefix (for NAT64), and Android reports its IPv6 capability for it, so the label can be true to the OS while no IPv6 traffic flows. Where the app can measure the difference it says so: "IPv4 only — OS claims IPv6, but no IPv6 address is reachable". Never treat that capability label as proof; only actually fetching your own IPv6 address is.
- Why is the public IPv6 row sometimes missing? It is only shown when an IPv6-only service actually answers with an IPv6 address; when that probe fails the stale value is cleared, so a v4-only network never shows a v6 address it cannot use.
- Author: Edward Poon
- Email: edward@hkt.cc
- Company: FOREWIN TELECOM GROUP LIMITED
- Location: HONG KONG, CHINA
- https://www.hkt.cc · https://www.say.cc
- Google Play: https://play.google.com/store/apps/details?id=com.paperclip.mtr
The published binaries are distributed under the terms stated in the release notes of the version you download. This repository is a distribution channel: it holds the installable APK, the changelog and the documentation only — no source code is published here, and the app is closed-source.