63 votes
Accepted

Can someone using the same DNS server as me hijack my domains?

Never you mind the comments section below, and never you mind the previous answers in the edit history. After about an hour of some conversation with friends (thank you @joeQwerty, @Iain, and @...
  • 32.4k
36 votes

Is there an example domain which is guaranteed not to exist?

As per RFC 6761 section 6.4, the domain invalid. and any names falling within .invalid., can be assumed not to exist.
  • 859
33 votes
Accepted

Does adjusting a domain name's TTL actually matter?

They're not supposed to, but some DNS services may treat this as more of a suggestion than a hard rule. They may honor the setting down to some minimum, or they may ignore your TTL completely and ...
  • 12.9k
32 votes

Can someone using the same DNS server as me hijack my domains?

In addition to Wesley's excellent answer, I'd like to add that there is already a solution to prevent this. It's called DNSSEC. The basics are this: You register your domain (I'll go with the ...
  • 27.5k
29 votes
Accepted

Spam emails regarding Domain Abuse Notices

This is spam at the least - at worst, it's a scam. Do not agree to send a read receipt. Do not download unnecessary content. Do not click links. Do not reply. Do not pass Go... etc. As others have ...
  • 410
22 votes
Accepted

List of top-level domains (TLDs) that require HTTPS connections, like .dev

A direct answer to this would eventually become outdated if more top-level domains start enforcing HTTPS using HTTP Strict Transport Security (HSTS, RFC 6797). Technically this is an HSTS policy of a ...
  • 44.6k
18 votes

Does adjusting a domain name's TTL actually matter?

Only if you make that change to the TTL more than three hours in advance of the IP address change. Remember that the TTL tells other DNS servers how long to cache records. So you must reduce it at ...
18 votes

Spam emails regarding Domain Abuse Notices

This is some attempt to spam/phish/infect with malware. Just delete it and carry on. There is no real way to avoid this crap, but you have your full contact information including mail in the domain ...
  • 97.9k
14 votes

Relation between "Registrar Registration Expiration Date" and the actual expiry

You hit probably one of the worst corner case of domain names, one that is often poorly explained everywhere and that causes a lot of problems. The following applies to gTLDs (some ccTLDs may work the ...
12 votes
Accepted

How to handle domains whose names shouldn't be published by certificate transparency?

I have a set of domain names that are used internally For internal only uses, you can set a private CA, install its certificate on internal systems, and issue internal certificates yourself. If your ...
  • 5,292
11 votes

Domain will not propagate (Over 96+ Hours)

I'm basically parroting Michael here, but this is too much to paste into a comment: ;sai.ngo. IN A ngo. 172800 IN NS b0.nic.ngo. ngo. ...
  • 32.1k
10 votes
Accepted

DNS security & .com AD Domains, What are the dangers to my AD Domain if someone squats my public .com domain

The potential security vulnerabilities of someone squatting your domain that you have AD hosted on ... are no different than the vulnerabilities from people squatting a domain with no AD on it. The ...
  • 37.1k
9 votes

Pointing a domain to AWS Route 53

Here is a simple process to get from registering a new domain to having browser requests arrive at the web server. Yes it could be made more fancy, but the focus is on simple in order to clear away ...
  • 245
9 votes

How many is too many name servers (ns)?

There is such a thing as "too many nameservers", but not for the reasons you're concerned with. The others have covered the irrelevance of latency concerns and I won't beat that horse to death. The ...
  • 32.1k
9 votes

Spam emails regarding Domain Abuse Notices

If you go to mxtoolbox, and check your domain for blacklisting, it doesn't return as listed on any at this time. You can check for blacklisting on: http://mxtoolbox.com/blacklists.aspx If you check ...
  • 2,691
8 votes
Accepted

DIG returns different result from different servers

For Google (8.8.8.8) as with many providers the resolving service gets load balanced over a number of nodes and as each node maintains it's own cache, subsequent queries to apparently the same name ...
  • 73.5k
7 votes

How many is too many name servers (ns)?

RFC2182 section 5 recommends at least 3 nameservers, and preferably no more than 7.
  • 7,746
7 votes

How many is too many name servers (ns)?

Let's be clear. Ever since the outage of a low cost low end provider of whatever you do not trust a technology that is proven. Why? You think everyone is as incompetent as GoDaddy? Never had a DNS ...
  • 51.1k
7 votes

Can someone using the same DNS server as me hijack my domains?

You'll be fine so long as you claim ownership of the domain at DigitalOcean (i.e. associate it with your account) before you tell the registrar to use their name servers. If someone has associated ...
  • 5,826
7 votes

CNAME working - but not for directories

It's not DNS CNAME problem. DNS only help clients to resolve IP from FQDN. If virtual host root works, then IP resolving works fine. You need to check you web server configuration, and web server ...
  • 3,265
7 votes

How to map a domain name to a load balancer in google cloud platform?

It seems to take time for gcp to know how to handle the new domain name. About some 15 minutes after the additional of the new A record, the domain name www.mycompany.com starts to work. The 404 ...
  • 3,096
6 votes

Why can't I whois '.google' domains?

There's no good reliable starting point for a WHOIS client. It's more or less an "illusion" that you can use whois without also specifying the whois server to query. I'll refer to my answer here ...
6 votes

How to set the domain name on GNU/Linux?

man hostname, being cited from its end to beginning FILES /etc/hostname Historically this file was supposed to only contain the hostname and not the full canonical FQDN. Nowadays most ...
  • 9,314
6 votes

How to handle domains whose names shouldn't be published by certificate transparency?

If leaking host names is part of your threat model, then CT is probably not the only source of such leakage. Think of email headers, logs, monitoring, compilers, .. lots of tools could eventually ...
  • 7,728
6 votes
Accepted

How to plan an Active Directory domain rename without it killing me?

If your organization changes and you need an entirely new directory structure, sure take the opportunity to pick a best practice DNS name. But you have not identified a problem, either technical or ...
6 votes
Accepted

How to responsibly discontinue receiving email at an old Internet domain?

As is noted already in the question, there is a conflict between the desire of not accepting incoming email and the idea of being able to contact the domain owner via email by convention-based email ...
5 votes
Accepted

Dig Command on specific server gives different results than querying without specifying a NS

To take away your worries: The domain is registered to you. Glue records are setup correctly. The zone is responding correctly from the configured DNS servers. It's hard to tell when it will be ...
  • 17.4k
5 votes

How to technically retrieve the full list of all domain names for a particular TLD?

In some sense one might argue that the "right" technical approach is to jump through whatever hoops the relevant registries require to get access to their TLD zone data or, if they do not have such a ...
5 votes

Do I have to specify new added domain in /etc/host?

The question, is simple : do I have to add an entry in my /etc/host file for that new added domain No.
  • 115k
5 votes
Accepted

Do I have to specify new added domain in /etc/host?

To expand on Iain's correct answer, in normal circumstances you rely on DNS and don't need anything in /etc/hosts and you certainly don't need to add each and every DNS entry and domain that points to ...
  • 73.5k

Only top scored, non community-wiki answers of a minimum length are eligible