Tobias Fiebig

Networking & Security; Misconfigurations, human factors, and Internet measurement; AS59645; Senioren Unix User🐡;

I am a system administrator turned network & security researcher, looking at digital infrastructures & society, and operators. Inspecting #cloudification at scale.

I am also operating a small hoster-ish AS for the good of the Internet (and to make it more distributed), making it ping. Happy to help non-profits with infrastructure.

Twitter: @chelloway
ASN: 59645
Blog: https://doing-stupid-things.as59645.net/
Website: https://fiebig.nl/

Public Key

npub13fpe053rvpmx3x7rapedl5hxlf2a4utajcufsg6al2lywtdm9hyq82s8zu

NIP-05 Address

tfiebig_at_wybt.net@momostr.pink

Profile Code

nprofile1qqsg5suh6g3kqangn0p7sukl6tn054w6797evwycydwl40j89kajmjqpz3mhxue69uhhyetvv9ujuerpd46hxtnfduqs6amnwvaz7tmwdaejumr0dsyplypu

Publishing to

saltivka.org

relay.damus.io

nos.lol

Author Public Key

npub13fpe053rvpmx3x7rapedl5hxlf2a4utajcufsg6al2lywtdm9hyq82s8zu

Show more details

Last Notes

2026-07-14 12:00:25 UTC

10001 is a beautiful number. 🙃

2026-06-26 19:34:51 UTC

It has been >>> 0 <<< days since i bit a simple bug in a fundamental software used by millions of people that is more than 2 years old...
or...
TIL: Rspamd cannot handle , in RUA for DMARC. -.-'
https://github.com/rspamd/rspamd/issues/4906

2026-05-18 16:11:02 UTC

It has been 0 days since i had to debug an incompliance in a major vendor's mail setup which people believed were a me thing. -.-'

2026-04-11 16:39:22 UTC

- reply

I actually started to do that to a DMCA takedown thing. Only stopped after I cc'ed finance to ask for their invoice address, insisting that them continuing to send (repeated, timed out) reports after I told them the next one will be charged was essentially agreement to my terms.

2026-04-11 16:29:13 UTC

There is just... SO MUCH... wrong with this.
https://wybt.net/system/media_attachments/files/116/387/013/342/820/455/original/db295fc34d7c2532.png

2026-01-23 12:29:07 UTC

RE: https://cyberplace.social/@GossiTheDog/115944285350406235
"Uncover" -> "Reads the documentation" 😬
#note1sjw…9zr9

2026-01-01 16:05:46 UTC

- reply

Turns out, i might not be alone: https://github.com/dani-garcia/vaultwarden/discussions/4182#discussioncomment-13542740

2026-01-01 15:54:51 UTC

Well, as I said... *checks notes* three days ago...
I de-googled by throwing out google password manager. If I now want to log into _my_ password manager... Google warns me that it is a dangerous site. -.-'
I find this... mildly unnerving. -.-'
#degoogle
https://wybt.net/system/media_attachments/files/115/820/647/869/874/027/original/61af8852f1127957.png

2025-12-28 09:37:19 UTC

RE: https://zirk.us/@ChrisMayLA6/115796068342655261
This is what makes (for me) [@PET_Symposium](https://infosec.exchange/@PET_Symposium ) ( https://petsymposium.org/ ) a real top-tier event. Same for @npub166s…t9zx conferences:
Self published full open-access (without additional charge beyond the conference registration; That these are, usually, too high (bit better at pets) is another discussion to be had... )
#note1jxr…3pgt

2025-12-26 10:31:48 UTC

Ok, hear me out; Stupid idea:
RBL for AI scrapers, but with BGP. I setup an auto-peering bgpd, and fill in the /32 | /128 of hosts i find scraping across my AS (+allow trusted entities to do the same).
Setup a remote peering with the host and nullroute that stuff.
Thoughts?

2025-11-25 16:58:17 UTC

- reply

munin-run? -.-'

2025-11-14 18:03:36 UTC

https://wybt.net/@npub1y04…5kh8/115535588938642568
"Amazon Data Services European Sovereign Cloud GmbH"... 🤣

2025-11-06 23:46:35 UTC

- reply

to be fair... the government shutdown was _not_ the issue for the 2023 one...

2025-10-29 22:38:58 UTC

Retrocomputing... 👀
https://wybt.net/system/media_attachments/files/115/459/849/636/736/401/original/e765dd73ecdbda06.png

2025-10-22 21:23:59 UTC

Guess who just added CDNSKEY/CDS records to all hosted zones... ^^

2025-10-17 06:50:54 UTC

It appears... that I will have a new affiliation in the future. And I guess after signing the contract it is pretty much official.
From the 1st of March 2026, I will be the full professor for 'Computer Networks' at #tuwien leading the 'Internet Infrastructures' research unit there.
A big thank you to everyone who supported me on my way there.
So, expect some interesting new research, and certainly some (applied) networking courses showing up in the curriculum. 🙂
#Wien #Vienna

2025-05-18 06:06:59 UTC

*sigh* I just learned goo.gl is shutting down (just the URL shortening service... )
*sigh*
Maybe I _should_ get shd.li going. ;-P
https://developers.googleblog.com/en/google-url-shortener-links-will-no-longer-be-available/

2025-04-17 06:59:08 UTC

Sooo, another takedown request for my domain fronting site for $news; Funnily enough, I would have never thought that these would come in the shape of copyright law, issued by the made-available sites. 🤷
Anyway... no more BBC on https://oedi.net/ it seems.

2025-04-14 15:29:27 UTC

"European universities urged to review dependence on top technology companies as Trump policies expose vulnerabilities" in Times Higher Education:
https://www.timeshighereducation.com/news/reconsider-reliance-us-tech-companies-universities-warned
Such discussions are increasingly taking place, Fiebig said, telling THE, “With the second Trump presidency, the risks [of depending on US providers] certainly did not change."
“What did, however, change is people's willingness to see that these risks are indeed real, and increasingly likely to materialise.”

2025-04-06 20:02:32 UTC

Well... seems like the https://www.professorwatchlist.org/ (Yes, it is a s bad as it sounds) is hosted on Google infrastructure and gets their DDoS protection from Cloudflare. Yay.
https://glauca.space/@q/114292722849141691
https://glauca.space/@q/114292687485239204
https://glauca.space/@q/114292711582658474
Now to the implications of putting academic infrastructure into the big clouds. -.-'

2025-03-20 16:35:15 UTC

https://boycott-ietf127.org/

2025-03-08 10:04:01 UTC

One last update: This is indeed a change of default behavior. I just pulled backups from Feb 28 (When still running v30);
The DB dump from Feb 28 does not contain configuration keys for files_sharing->lookupServerUploadEnabled and files_sharing->lookupServerEnabled. Neither does the SQL dump from Mar 7 (after the upgrade and before event detection, i.e., while data was transmitted).
-.-'

2025-03-08 00:30:54 UTC

Just had some non-fun following up on Niels' post ( https://bsd.network/@niels/114106538216130985 ) about weird requests after upgrading to #Nextcloud 31.0.0.
TLDR: NC 31.0.0 seems to share user data by unclear-maybe-default for federated sharing (public access?). May include sensitive PII (Phone, Email, Address) based on settings.
To prevent this, set Admin Settings > Sharing > Federated Cloud Sharing > Allow people to publish their data to a global and public address book to off
Write-up: https://doing-stupid-things.as59645.net/nextcloud/self-hosting/dataleak/2025/03/08/es-ist-alles-in-der-next-cloud.html

2025-03-04 14:25:50 UTC

How it started:
https://wybt.net/@tfiebig/114057953988656610
How it is going: ...
Todo next year: Force the students to do proper cabling... -.-'
https://wybt.net/system/media_attachments/files/114/104/616/169/673/795/original/dc963ce02b719536.png

2025-02-24 08:37:40 UTC

The router lab from MPI INF/Inet mostly taught and supervised by our post-docs Tiago and Taha is kicking off today! Bringing 16 students to the Internet; The proper way: With an ASN, a /24, and a /48 per group of two, all publicly routed. ^^
https://wybt.net/system/media_attachments/files/114/057/892/474/199/479/original/661d1b0d12cb11e9.jpg

2025-02-20 23:57:51 UTC

Given world events some time ago, i started running some reverse proxy thing (See: https://github.com/ichdasich/rev_prox ) for some news websites and otherwise useful resources on tudasnich.de ;
Well, guess who just got a take-down request from 'The Guardian'. <3
Well, one site less to proxy, i guess.

2025-02-18 22:17:07 UTC

Would there be interest in a dedicated mastodon instance where the _core_ rule is: #Cat #CatsofMastodon #caturday Content only? (bots welcome) 🐈

2025-02-18 11:11:31 UTC

- reply

Well, the underlying truth is that the holocaust was fundamentally enabled by what we call "IT people" today.
And for some reason, nobody in IT got that memo and happily collects (meta) data without thinking about the possible dire consequences.
You can't lose data you don't have.

2025-02-18 10:30:43 UTC

- reply

Actually; Even more so in the Netherlands. The Dutch had migrated to a fully IBM/Hollerith Machine backed public administration ('digital' first, bedenken second oder so) before the invasion. After the invasion, the German's were just like "uuuuh, we know these machines! Got a query to run, let's call our IBM consultant!";
This is why (by %/population) so many more were murdered in NL; And why the Dutch resistance burned archives:
https://www.annefrank.org/en/timeline/128/the-resistance-attacks-the-population-register-of-amsterdam/
https://en.wikipedia.org/wiki/1943_Amsterdam_civil_registry_office_bombing

2025-02-15 10:15:33 UTC

WTF... o.O "Another Corporate ISP, LLC"?
"University of Lynchburg" transferred 161.115.48.0/20 (Taken from 161.115.0.0/16) to "Another Corporate ISP, LLC"
(Estimated Market Value: $131.07 K)
https://social.bgp.tools/@transfers/statuses/01JM4HADSS9708NDD0A5HN769V

2025-02-05 10:35:32 UTC

- reply

Sample Answer:
1) Verify that you understood your boss’ request correctly; get it *in writing*
2) Verify if the request is illegal and/or in violation of ethical conduct
3) If possible, assertively, yet politely, refuse taking the illegal/unethical action
4) Prevent the illegal/unethical action, in this case, e.g., by leaking the database to the press or delaying action for operative reasons; Considerations apply. 5/N

2025-02-05 10:33:19 UTC

- reply

4.a) Your boss approaches you, and they ask you to properly delete that database stored in SWS EC2, to prevent the reunification of parents and children. How do you handle this? (4 points) 4/N

2025-02-05 10:32:45 UTC

- reply

While the children were initially held in cages, public pressure forced LIQUID to ending this policy. Hence, they started to offer these children for adoption to local families, while deporting the parents. Currently, the public lobbies to have these children reunited with their deported parents. The database connecting these children and their deported parents is stored with SWS EC2. 3/N

2025-02-05 10:30:53 UTC

- reply

4 Handling responsibility (6 points)
You are managing the Schwartzwald Web Services EC2 (SWS EC2) team, which provides IT services to LIQUID (Local Immigration Quantification, Uniformity, and Integration Department), your national anti-immigration police. LIQUID recently started to separate children of foreigners planning to migrate to the country you are living in at the border. 2/N

2025-02-05 10:30:18 UTC

Back in 2019/2020 when I was teaching a course for more (in the governance sense) administration focused students, I had some questions in my exams students back then considered 'grossly exaggerated' and 'unlikely to ever happen'.
Given *gestures at everything*, i figured it might be good to post them (including the sample solutions).
So, here we go, little thread trying to put questions into toots. 1/N
https://wybt.net/system/media_attachments/files/113/950/798/899/090/772/original/822d7e2eb69cc91f.png

2025-01-16 17:06:01 UTC

- reply

2025-01-16 16:50:53 UTC

- reply

I have to say, I only had the second post show up in my feed. With both messages, of course you are not. 🙂

2025-01-16 16:47:54 UTC

- reply

As i said, so is AS3320, so it may also be the Germans by that reasoning.
Also, i don't suspect Iran to be that... well... simple to just scrap themselves. Scrapping a usual suspect from a dataset to poke suspicion, though... might also be on the plate for some. ;-P
In any case, I'd be a bit more conservative with attribution. ;-P

2025-01-16 12:19:08 UTC

- reply

I find the absence of, e.g., 3320 in that list a bit odd.

2025-01-11 13:59:35 UTC

Idea: Setup Akvorado
Problem: Github has no v6
Problem 2: How do i tell a linux box to use a pref64 given static adressing (Debian 12)?
Anyone got some hints? @npub1l8t…mz8s maybe? 😕

2024-12-21 16:04:49 UTC

- reply

Yeah, but do you wear a helm while biking?

2024-11-15 17:03:55 UTC

Can somebody recommend a good lawyer for privacy things in the Netherlands?

2024-11-10 19:38:54 UTC

- reply

Same for "cyber" please... 🥺

2024-09-14 08:00:49 UTC

- reply

Favorite statement in the same line of thought: "The plural of 'anecdote' is not 'proof'." 😬😁

2024-09-06 17:02:43 UTC

https://futurism.com/the-byte/ai-startup-rickrolling
The article says:
>>>
"The really remarkable thing about this new age of AI is, to patch it, all I had to do was add a line for what we call the system prompt — which is the prompt that’s included in every Lindy — and it’s like, don’t Rickroll people," he continued.
<<<
Oh well... how shall i tell you... there is so much more than just rick-rolling. There is SO much WORSE... this will become a loooong prompt.