this post was submitted on 26 Aug 2026
352 points (100.0% liked)
Programmer Humor
32965 readers
1679 users here now
Welcome to Programmer Humor!
This is a place where you can post jokes, memes, humor, etc. related to programming!
For sharing awful code theres also Programming Horror.
Rules
- Keep content in english
- No advertisements
- Posts must be related to programming or programmer topics
founded 3 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
tcpdump looks scary but is super neat and helpful, learn it if you haven't ;)
ack
Still doesn't help with things like understanding routing and subnet masks and frame sizes and jfc how does any of this work
Of course not, but I've found that seeing the protocols in action and looking at real headers can be very helpful in making them click. Understanding DHCP or ARP or mDNS or BGP or whatever is much easier by inspecting a pcap than it is by reading RFCs
Yeah, for this, I started with this and this. With that said, it's still mostly arcane witchcraft. 🤣
As someone who understands the concept of network but has never professionally entered the field, i assume this just dumps a TCP packet to be inspected, correct?
The tcpdumps I've worked with can also dump UDP, ICMP, and even ARP.
Tcpdump can also capture USB traffic!
Yes, but before I used it I assumed that its scope was pretty much limited to what you just mentioned. Instead it can operate on most protocols both above and below layer 4, and it is incredibly useful as a traffic capture tool to produce a
.pcapon a remote headless machine which you can then load into Wireshark. The "dump" part is the interesting one, not the "tcp" ;)Yes. Also learn about certs if you need to deal with encryption https etc.
Thank you for the affirmation, I got reverse proxies and certificates relatively down, however I am struggling to understand headers and their purposes, I know Mozilla has great documentation regarding headers but lately I’ve gotten lazy, haha.
HTTP headers or headers in general? For the former I suggest Burp Suite to inspect and manipulate headers to see how things change, for the latter tcpdump/wireshark, to supplement your theory reading :)
Thanks! I started with Wireshark, settled on tcpdump for a while and now I'm too busy learning electrical engineering to give any fucks at all. 🤣 Nah but seriously, tcpdump gave me lots of insight! :)
Electrical engineering is just layer 1 on the OSI model.