When I was talking my cyber security / ethical hacking class, we learned how to do zone transfer. The concept never stuck and I basically “copy” from my friend. So what exactly is a DNS Zone Transfer?
Comment on Welp that answers a lot of why all .ml are down
grandkaiser@lemmy.world 1 year ago
Hi, professional DNS engineer here! if anyone has any questions about the inner workings of DNS or top level domains, ask away!
jmanjones@lemmy.world 1 year ago
grandkaiser@lemmy.world 1 year ago
Friday I was doing a zone transfer! What are the odds?
A zone transfer is like moving houses, except for an authoritative zone.
In DNS, we have what’s called an authoritative zone. That means the device hosting the “resource records” (all the data that DNS passes around) is the “ultimate” answer. I.e, it’s not cached data. It’s not a hosts file. It’s not a recursive answer. It’s the real deal.
When you want to move the authoritative zone to another server, you do a “zone transfer” that means the new server will copy all the resource records over TCP from current authoritative zone. The reason you may want to do this instead of manually hand-jamming it is that many large organizations have, sometimes, hundreds of resource records (last month I coordinated a zone transfer that was over 1000 records!).
jmanjones@lemmy.world 1 year ago
Why would a hacker want to zone transfer?
sol87@lemmy.world 1 year ago
Well that sounds like my dream job, unfortunately this issue in particular is more of a Lemmy problem, not a DNS problem. See: lemmy.nrd.li/comment/190200 for the explanation of why you cant just transfer domains with Lemmy.
grandkaiser@lemmy.world 1 year ago
Also, if you’re genuinely interested in this field, first you should enter the world of enterprise network engineering. Get Security +, CCNA, and PCNSA. With those certs in hand (and knowledge in your brain), apply to jobs as a network support engineer. Do the work for a few years. Learn BIND. Learn Infoblox. Focus on learning DHCP and subnetting. Learn DNSSEC & IPv6. Experiment with a Pi Hole. Set up a home lab. Apply to jobs with DNS. Start living the good life.
sol87@lemmy.world 1 year ago
I only just now saw this post, the last month i have already been going all out to learn everything that i need for my Security+ (then CySec+) i have a 30hr video course im part way thorugh, and ive set up a few VMs with various servers like OWASP Security Shepherd and Dam Vunurable Web App for some more hands on experience as well as testing on my personal production Nextcloud and Jellyfin servers and ive been having alot of fun with it all, i think im pretty solid with DHCP and subnetting already through my home networking adventures. I will look into each of those other Certs and each thing you mention to learn thank you! Ive been deep into various Linux systems since about 2008 and im hoping to leverage that as much as i can(although its left me with a lack of modern Windows experience).
Thank you so much for all the tips! I feel some good things coming as im getting into this as work.
grandkaiser@lemmy.world 1 year ago
Ah, thanks for the info! I have no idea how Lemmy stuff works. I only became aware of Lemmy last month.
Gatsby@lemm.ee 1 year ago
So why do we need the .com or .org or whatever at all? And the www. as well?
I remember when I had to type the whole www.cakefarts.com and now just cakefarts.com works. What changed? And what’s next?
MimicJar@sh.itjust.works 1 year ago
The “.com” and “.org” and all other Top Level Domains are owned/controlled by some organization.
Com and org are your original TLDs, so since they were around first you see them everywhere. At some point countries got their own TLDs so Mali got “ml” for example but Tuvalu got “tv”. (Yes, technically “.tv” has nothing to do with television.) And a few years back there was open bidding for a bunch of new TLDs which is where “.sport” or “.dentist” come from.
Anyone some entity owns/controls them and then can sell any word or domain under it. So if you want “greatgatsby.com” you have to talk to the “.com” owners. If you want “greatgatsby.sport” you talk to the “.sport” owners. Usually there is another company or agreement that groups these together so you can manage all your domains in one place.
So anyways now you own a domain like “greatgatsby.sport”, what do you want to host? Mail at “mail.greatgatsby.sport”? A website at world wide web aka “www.greatgatsby.sport”? Up to you.
Over time, largely by convention “www” became where you put your website.
From there you have two options, you can setup a redirect from “greatgatsby.sport” to “www.greatgatsby.sport” or you can do a little hosting “trick” and just make “greatgatsby.sport” return your website.
tchotchony@mander.xyz 1 year ago
So say I want a “.travel”, who actually makes and sells these? Is it a private company? A country? An independent entity who’s sole purpose it is to keep domains and the interwebs alive?
grandkaiser@lemmy.world 1 year ago
Btw, .com is owned by the US Department of COMmerce. .org is owned by a non-profit organization called “Public Internet Registry”
grandkaiser@lemmy.world 1 year ago
To answer your other question, www.cakefarts.com is now accessible from cakefarts.com for one of two reasons:
- Your web browser automatically checks the A record “www” if “cakefarts.com” doesn’t have an A record. A records are the records in a DNS server that says "this domain goes here"
- The site cakefarts.com put their website on cakefarts.com and placed a CNAME record called “www” that points to cakefarts.com
- cakefarts.com has an APEX record that points to www.cakefarts.com
For the ‘record’, www is just a really common record name. There’s nothing special about it. You could have dudebro.cakefarts.com or wwwwwww.cakefarts.com. It’s up to the domain owner.
letsalllovelain@discuss.tchncs.de 1 year ago
Hi! When DNS servers are launched, they have to be purchased, correct? So in this case, did Mali file for the domain to be reclaimed somehow? Do you have an idea how that might work?
toasteecup@lemmynsfw.com 1 year ago
I can answer this. The organization that says mali owns .ml gives the ownership country a lot of sway.
So if the country of mali were to reach out formally to the organization and say “hey this domain violates our laws” they would take that very seriously and then work with the registrar & authoritative nameserver owner to handle the situation.
I’m sure this isn’t 100% accurate but 90-95 based on my work in a web hosting company
grandkaiser@lemmy.world 1 year ago
It’s a little stronger than that. The country gets the final say on where the root zones point to when it comes to their assigned country code. Many countries employ private organizations to handle their TLD. They aren’t supposed to be paid for that though. (But it 1000% happens under the table)
Spruce1538@lemm.ee 1 year ago
How can a website know exactly what dns they were accessed from or if they were accessed directly through IP?
grandkaiser@lemmy.world 1 year ago
They don’t know unless the DNS server tells them. For example, a very popular webhost Akamai uses a complex DNS + web hosting suite (DNS edgesuit to be exact) to send that type of data to the web servers. It can also allow for many many other features.
cloud_punk@lemmy.world 1 year ago
Why is it always dns
starman@programming.dev 1 year ago
So, how some companies get right to sell TLDs? Can I start selling TLDs nowdays? It’s just that they were there first and get all top level domains and now we have to pay for it?
Thanks in advance.
lazylion_ca@lemmy.ca 1 year ago
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Could users set a temporary entry in their hosts file pointing the .ml domains to public IPs in order to regain access to their account if they needed to?
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Can Lemmy federate to an IP address directly or will the settings only accept an fqdn?
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Will a Lemmy instance work behind a reverse proxy.
Thanks for taking the time to answer questions.
sol87@lemmy.world 1 year ago
There are several problem with this including total lack of SSL without the proper cert for that other domain, also Lemmy.ml’s IP seems to be running a reverse proxy so the internal IP that we would want to connect to is not visible to the world this is common for web security, the owners must set allowed domains and ports in their config file.
If none of that was a problem Lemmy itself does not do well with changing domains, as highlighted here: lemmy.nrd.li/comment/190200
grandkaiser@lemmy.world 1 year ago
- Yes. Unless there’s some kind of crazy domain-level hi-jinks involved with Lemmy (I am not versed in Lemmy), pointing directly to the IP will work if you bypass it by spoofing your DNS (Hosts file, for example).
- I don’t know how Lemmy federation works, sorry :(
- See #2
Sorry that I couldn’t answer more of your questions.
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widdle@lemmynsfw.com 1 year ago
How does the TLD get reclaimed? I’m assuming whoever was previously the “owner” of the .ml tld was on board and Mali didn’t just come along and snatch it away?
grandkaiser@lemmy.world 1 year ago
So here’s the thing about TLD’s, ownership of them is determined by IANA (Internet Assigned Numbers Authority). They’re basically my career’s gods. If they tell me to jump, I ask “how high”. They control the DNS root zone. Effectively, that’s the actual top-level of ALL domains. If they decide to remove a TLD or reassign it, all you can do is lodge a complaint straight to their shredder. They’re owned and operated by ICANN, a non-profit organization.
Back in 2013, Mali allowed a private Netherlands company to “manage” (rent) their TLD, .ML Recently, that company (Freenom) got sued by Meta. Even though I don’t really like Meta, as a network engineer, I don’t like Freenom even more. They turn a blind eye to bad actors on the internet, refuse to investigate hackers/scammers/DDOSers, and generally refuse to play ball. They are a huge pain in the ass. Due to the lawsuit, IANA reassigned ML to Mali since they asked for it. At the end of the day you “cant” sell a country-level TLD. Mali was renting it to Freenom under the table. This happens a lot and IANA usually just looks the other way. .io for example is the freakin’ Indian Ocean.
So yeah, Mali didn’t “snatch” it. They just asked IANA to reassign it and there isn’t shit Freenom can do about it.
salient_one@lemmy.villa-straylight.social 1 year ago
What’s the point of alternative DNS roots? Can they be a thing to mitigate DNS related failures (though lemmy.ml is back online, so I guess that wasn’t it)?
grandkaiser@lemmy.world 1 year ago
An alternative DNS root is where someone other than IANA sets up a root zone. At the end of the day, root zone authority is technically not “hard coded”. It’s a terrible idea to set up an alt root or to use one for these reasons:
To answer your second question, they are not good for acting as a way to mitigate DNS failures. No domain servers are going to be asking them in the first place, meaning no one can get there even if it does have the “correct” answer. If all 13 root servers went down simultaneously, the results would be catastrophic. But that’s also why they’re physically located around the world in many different countries in heavily secure facilities with many High-Availability servers (clone servers that instantly take over if there’s a failure, the ultimate “hot” server)
You wouldn’t want to have a DNS server ask two root zones anyway. If it can’t reach the root zones, then that needs to be addressed. You can’t just ask a “less secure” server in case the primary doesn’t work. That’s just begging for a security breach via cutting off access to the primary root zones so that they “fail over” to the less secure ones.
salient_one@lemmy.villa-straylight.social 1 year ago
Thank you for such a detailed and instructive answer!