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Questions tagged [subdomain]

In the Domain Name System (DNS) hierarchy, a subdomain is a domain that is part of a larger domain.[1]

The Domain Name System has a tree structure or hierarchy, with each node on the tree being a domain name. A subdomain is a domain that is part of a larger domain, the only domain that is not also a subdomain is the root domain.

For example, mail.example.com and calendar.example.com are subdomains of the example.com domain, which in turn is a subdomain of the com top-level domain (TLD).

A "subdomain" expresses relative dependence, not absolute dependence: for example, wikipedia.org comprises a subdomain of the org domain, and en.wikipedia.org comprises a subdomain of the domain wikipedia.org.

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Wildcard SSL certificate for second-level subdomain

I'd like to know if any certificates support a double wildcard like *.*.example.com? I've just been on the phone with my current SSL provider (register.com) and the girl there said they don't offer anything like that and that she didn't think it was…
Rob Long
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What type of DNS record is needed to make a subdomain?

I'm making a website, and I need a sub-domain. I need to add the new part to my website, but I don't know which type of DNS record to add in the DNS console to point to this new site. Is it A or CNAME?
Keavon
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Does each subdomain need it's own SSL certificate?

I am creating a websocket server which will live on ws.mysite.example. I want the web socket server to be SSL encrypted as well as domain.example to be SSL encrypted. Do I need to purchase a new certificate for each subdomain I create? Do I need a…
user974407
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How do I redirect subdomains to a different port on the same server?

I have some subdomains I want to redirect to specific ports on the same server. Say I have dev.mydomain.com I want dev.mydomain.com to transparently redirect to mydomain.com:8080 and I want to preserve the original sub-domain name the url of the…
user35861
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Is there a maximum subdomain depth?

Is there a maximum allowed subdomain depth supported by webservers or browsers? For example, could a domain like foo.bar.baz.monkey.pirate.google.com cause problems?
braveterry
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subdomain of a subdomain?

I am trying to create url like sub2.sub1.subdomain.domain.com. I am planning to use this to display different content. my questions are... 1) Is it possible to create such multi level sub domains? - is this based on the hosting company? 2) Isn't…
Chris Job
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Wildcard vhosts on Nginx

I've just installed Nginx on my server and am extremely happy with the results, however I still cannot figure out how to insert wildcard virtual hosts. This is the [directory] structure I'd like: -- public_html (example.com) ---subdoamin 1…
rorygilchrist
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How did someone point a sub-domain of our domain to someone else's IP address?

We own a primary domain: businessdts.com I didn't know if our admins had created a sub-domain I had requested, "BDASERVER.businessdts.com.", so I just tried to connect to it with a browser and got a "not found". Then I pinged that sub-domain and…
CBruce
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If I own a domain do I own all of its sub domains?

If I own a domain do I own all of its sub domains? For example if I purchase example.com, do I automatically own mail.example.com, blog.example.com, etc? If I do not own the sub domains, can anyone buy mail.example.com if I own example.com? Do I…
Matthew Fournier
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How do you have one IP address and many websites?

How can I have it where I have one IP address that sits on the Internet but many web names? For example, when a hosting company has a shared IP but I get unlimited domain names (along with everyone else on that box). I have a box on the Internet but…
johnny
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Is a wildcard DNS record bad practice?

I asked my hoster to add three subdomains all pointing to the IP of the A record. It seems he simply added a wildcard DNS record because any random subdomain resolves to my IP now. This is OK for me from a technical point of view, since there are no…
problemofficer - n.f. Monica
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How to reverse proxy to different places depending on subdomain in Nginx?

I have multiple subdomains, all pointing to one machine, and one IP address. On this machine, I want to have nginx acting as a reverse proxy, and depending on which subdomain was used to access the machine, I want it to reverse proxy to a different…
markasoftware
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Do intermediate subdomains need to exist?

If I have the hosts example.com and leaf.intermediate.example.com in DNS records for example.com, but do not have any records for intermediate.example.com itself, does that cause a problem in some situations or is it bad style or etiquette for some…
Lassi
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Amount of allowed subdomains in domain and email

How many subdomains can you have on your domain? And with that, I mean levels of subdomains. For example, you have the domain example.com, I know you can have test.example.com, but how many levels can you have? Like test2.test.example.com,…
Joshua Bakker
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Can subdomain.example.com set a cookie that can be read by example.com?

I simply cannot believe this is quite so hard to determine. Even having read the RFCs, it's not clear to me if a server at subdomain.example.com can set a cookie that can be read by example.com. subdomain.example.com can set a cookie whose Domain…
Evan Plaice
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