Hopscotch — Network Path Intelligence

Capabilities

Every flag. Every hop. Total visibility.

Hopscotch turns every TTL increment into actionable intelligence. Real features, enterprise scale.

🌐

Path Discovery Engine

Traces the exact route packets take from origin to destination, eliciting ICMP TIME_EXCEEDED responses from every gateway along the way. See the full topology.

core

🔢

Hop Ceiling Control `-m`

Set the maximum number of hops with surgical precision. Default 30, configurable to any depth. Stop wasting cycles probing past your network boundary.

-m max_ttl

📡

Multi-Probe Intelligence `-q`

Send multiple probe packets per hop for statistically significant RTT measurements. Three probes by default — tune to your confidence interval.

-q nqueries

⏱️

Adaptive Timeout `-w`

Smart wait-time algorithms with three-tier sensitivity: max, here, and near factors. Eliminate premature timeouts without wasting seconds on dead hops.

-w max[,here,near]

🏷️

AS Path Lookups `-A`

Perform autonomous system path lookups in routing registries and print results directly after corresponding addresses. Map the organizational topology of the internet.

-A

📏

MTU Discovery `--mtu`

Discover Maximum Transmission Unit along the traced path. Implies don't-fragment mode. See exactly where packet size bottlenecks live in your route.

--mtu

⚡

Parallel Probing `-N`

Send up to 16 simultaneous probe packets. Dramatically accelerate trace execution without sacrificing accuracy. Speed and precision, together at last.

-N squeries

🎯

First-Hop Targeting `-f`

Skip irrelevant near-side hops by setting the initial TTL. Start your analysis exactly where it matters — not from hop one every time.

-f first_ttl

Process

From probe to insight in milliseconds.

Launch Probes

Hopscotch sends probe packets with incrementally increasing TTL values, starting from 1. Each packet is designed to expire at the next gateway in the chain.

Capture Responses

Each gateway returns an ICMP TIME_EXCEEDED reply, revealing its IP address and hostname. Three probes per hop yield statistically robust round-trip measurements.

Map The Path

Responses are assembled into a complete hop-by-hop topology. Timeouts are flagged, AS numbers are resolved, and MTU bottlenecks are identified.

Deliver Intelligence

The full route is rendered with each hop's address, latency, annotations, and unreachability codes — giving you a first-principles view of your network topology.

Protocol Engines

Four tracing methods. One platform.

Firewalls filter what they can't understand. Hopscotch adapts, using the protocol that gets through.

Capability	UDP `default`	ICMP `-I`	TCP `-T`	UDP Const `-U`
Firewall bypass	Limited	Moderate	Excellent	Good
Default port	33434+	N/A	80 (HTTP)	53 (DNS)
Custom port `-p`	✓	—	✓	✓
Half-open technique	—	—	✓	—
Unprivileged users	✓	✓ (kernel 3.0+)	—	✓
Destination visibility	Port unreachable	Echo reply	SYN+ACK / RST	Varies
Best for	General use	Standard tracing	Firewall evasion	DNS routes

Live Demo

Hop-by-hop, millisecond by millisecond.

hopscotch — Network Path Intelligence

$ hopscotch -A -I google.com

hopscotch to google.com (142.250.80.46), 30 hops max, 60 byte packets

1 192.168.1.1 (192.168.1.1) [AS0] 2.438 ms 1.921 ms 1.764 ms

2 10.0.0.1 (10.0.0.1) [AS7018] 8.126 ms 7.943 ms 7.812 ms

3 72.14.215.85 (72.14.215.85) [AS15169] 12.643 ms 12.219 ms 11.987 ms

4 * * *

5 209.85.249.19 (209.85.249.19) [AS15169] 24.318 ms 23.891 ms 23.654 ms

6 142.250.80.46 (142.250.80.46) [AS15169] 25.112 ms 24.876 ms 24.543 ms

Hop-by-Hop Analysis

Hop	Gateway	AS Number	Probe 1	Probe 2	Probe 3	Status
1	`192.168.1.1`	—	2.438 ms	1.921 ms	1.764 ms	●
2	`10.0.0.1`	AS7018	8.126 ms	7.943 ms	7.812 ms	●
3	`72.14.215.85`	AS15169	12.643 ms	12.219 ms	11.987 ms	●
4	`* * *`	—	*	*	*	●
5	`209.85.249.19`	AS15169	24.318 ms	23.891 ms	23.654 ms	●
6	`142.250.80.46`	AS15169	25.112 ms	24.876 ms	24.543 ms	●

What People Say

Trusted by network teams that ship.

"Hopscotch's TCP probing mode completely changed how we debug firewall traversal. We went from blind spots to full path visibility in one afternoon. This is a category-defining tool."

Sofia Petrov VP of Infrastructure, ScaleForge

"The AS path lookup feature alone saved us three engineering sprints. We finally understand where our packets go after they leave our network edge. 10x improvement, no exaggeration."

Raj Krishnamurthy CTO, DataMesh

"I'm a solo developer running a side project and Hopscotch's free tier gives me 30 hops of pure visibility. The MTU discovery feature caught a fragmentation issue that had been haunting me for months."

Marcus Tremblay Solo Developer

"The parallel probing engine is world-class. We trace 200+ routes per minute across four protocol engines. Our NOC team can't imagine going back to the dark ages before Hopscotch."

Tobias Whitfield Director of Network Ops, NexLayer

Pricing

Scale your path intelligence.

Start free. Upgrade when your network demands it.

Starter

Free

For individual developers exploring their network.

Up to 30 hops per trace
UDP protocol only
1 probe per hop (-q 1)
Numeric output only (-n)
10 traces per day

Get Started

Questions? Answered.

What does the * mean in my trace output?

An asterisk (*) indicates a timeout — the gateway at that hop did not respond within the configured wait time. This is common with firewalls that drop ICMP TIME_EXCEEDED messages. It doesn't necessarily mean the hop is down; try switching protocols with -T (TCP) or -I (ICMP) to probe through filtered paths.

How does Hopscotch bypass firewalls?

Our TCP engine (-T) uses a half-open technique — sending SYN packets to common ports like 80 (HTTP) or 25 (SMTP) that firewalls must allow. The destination never sees a full connection. For DNS-filtered networks, our constant UDP mode (-U) targets port 53 by default.

Is my data secure during tracing?

Absolutely. Hopscotch probe packets contain no user payload data. We send minimal probe packets (60 bytes for IPv4, 80 bytes for IPv6) with only TTL-manipulation headers. Your routing data is processed locally and never leaves your infrastructure unless you explicitly enable cloud sync.

Can I trace both IPv4 and IPv6 paths?

Yes. Hopscotch automatically detects the appropriate protocol from the destination hostname. You can also force IPv4 with -4 or IPv6 with -6. Our IPv6 mode is fully equivalent with complete source routing and flow label support (-l).

What's the difference between the four protocol modes?

UDP (default) sends datagrams to unlikely ports starting at 33434. ICMP (-I) uses echo requests. TCP (-T) sends SYN packets with half-open technique for firewall evasion. Constant UDP (-U) targets a fixed port (default 53/DNS). Each has different firewall transparency profiles — see our Protocol Comparison chart above.

See every hop between
you and the answer.

Every flag. Every hop. Total visibility.

Path Discovery Engine

Hop Ceiling Control `-m`

Multi-Probe Intelligence `-q`

Adaptive Timeout `-w`

AS Path Lookups `-A`

MTU Discovery `--mtu`

Parallel Probing `-N`

First-Hop Targeting `-f`

Watch your packets travel.

From probe to insight in milliseconds.

Launch Probes

Capture Responses

Map The Path

Deliver Intelligence

Four tracing methods. One platform.

Hop-by-hop, millisecond by millisecond.

Hop-by-Hop Analysis

Trusted by network teams that ship.

Scale your path intelligence.

Questions? Answered.

See mandō's portfolio

Coming Soon

See every hop betweenyou and the answer.

Every flag. Every hop. Total visibility.

Path Discovery Engine

Hop Ceiling Control -m

Multi-Probe Intelligence -q

Adaptive Timeout -w

AS Path Lookups -A

MTU Discovery --mtu

Parallel Probing -N

First-Hop Targeting -f

Watch your packets travel.

From probe to insight in milliseconds.

Launch Probes

Capture Responses

Map The Path

Deliver Intelligence

Four tracing methods. One platform.

Hop-by-hop, millisecond by millisecond.

Hop-by-Hop Analysis

Trusted by network teams that ship.

Scale your path intelligence.

Questions? Answered.

See mandō's portfolio

See every hop between
you and the answer.

Hop Ceiling Control `-m`

Multi-Probe Intelligence `-q`

Adaptive Timeout `-w`

AS Path Lookups `-A`

MTU Discovery `--mtu`

Parallel Probing `-N`

First-Hop Targeting `-f`