I Built where-is-my-packet to Make Linux Network Debugging Less Painful

Published at 2026-03-28 | Last Update 2026-03-28

• The Problem I Wanted to Solve
• Why Existing Tools Were Not Enough for Me
• What where-is-my-packet Is Trying to Do
• Built From a Real Pain Point
• What I Hope It Becomes
• Final Thoughts

I started from frustration.

Over and over again, when I was debugging Linux network issues, I ran into the same problem: there wasn’t a tool that helped me quickly answer a very basic question:

What is happening to this packet on this host?

Instead, the workflow usually looked like this:

• Check ip route
• Check ip rule
• Check iptables
• Run tcpdump
• Look at everything again
• Try another angle
• Repeat

None of these tools are bad. In fact, they are essential. But when you are in the middle of troubleshooting, they often force you to reconstruct the full story manually. Each tool shows one piece of the puzzle, and you have to stitch them together in your head.

That process is slow. It is fragmented. And sometimes, it takes much longer than it should just to locate where the real problem is.

So I built where-is-my-packet.

The Problem I Wanted to Solve

When debugging networking issues on Linux, the hard part is often not collecting information.

The hard part is turning scattered information into an explanation.

You may have routing rules. You may have firewall rules. You may have multiple interfaces, policy routing, or packet filters that interact in unexpected ways. You may even have the right tools already, but still spend a lot of time jumping between them just to answer:

• Which path would this packet take?
• Which rule affects it?
• Is it being forwarded, dropped, or rejected?
• Where should I look next?

I wanted something that could help me get to that answer faster.

Not by replacing existing tools, but by reducing the amount of manual cross-checking between them.

Why Existing Tools Were Not Enough for Me

My usual debugging flow depended on several excellent tools:

• ip route
• ip rule
• iptables
• tcpdump

But in practice, each of them answers a different question.

tcpdump tells you what you can observe on the wire.
ip route tells you routing decisions.
ip rule tells you how policy routing is applied.
iptables tells you filtering and packet handling logic.

The issue is that real debugging usually needs all of these at once.

When a packet does not go where you expect, you do not want four separate partial answers. You want one usable explanation.

That gap is what pushed me to start this project.

What where-is-my-packet Is Trying to Do

The goal of where-is-my-packet is simple:

Given a packet, help me understand how the host would handle it and where the problem likely is.

That is the core idea.

I wanted a tool that could take the mental debugging process I kept doing by hand and make it more direct. Instead of bouncing between commands and piecing together clues, I wanted something that could help narrow the search space quickly.

This project is not about replacing the standard Linux networking toolbox. Those tools are still the foundation.

It is about making the first step of troubleshooting faster:

• locating the problem
• understanding the likely path
• getting a more direct explanation of what the host is doing

Built From a Real Pain Point

What I like most about this project is that it did not come from an abstract idea.

It came from a repeated annoyance in real debugging sessions.

I kept running into situations where I thought:

There should be a faster way to figure this out.

After enough of those moments, I stopped looking for the tool and decided to build it.

I think many useful developer tools begin this way. You are not trying to create something impressive. You are trying to remove friction from your own workflow. You build the thing you wish you had yesterday.

That is exactly what where-is-my-packet is.

What I Hope It Becomes

Right now, the project is my attempt to make Linux network debugging more approachable and less time-consuming.

My hope is that it can be useful to others who run into the same class of problems:

• issues that are not obvious from a single command
• issues that require checking several layers of configuration
• issues where finding the problem takes more time than fixing it

Even shaving off a meaningful amount of debugging time would make this tool worthwhile to me.

Final Thoughts

I did not build where-is-my-packet because I wanted to make “another networking tool.”

I built it because I was tired of spending too much time switching between ip route, ip rule, iptables, tcpdump, and other commands just to answer one simple question:

Where is my packet, and what is the host doing with it?

That question became the project.

And that is the origin of where-is-my-packet.