18

A CNAME is a type of DNS record, where a hostname points at another hostname. An A record is another type of DNS record, where a hostname points at an IP address. A subdomain is what you described as 'the left side of the domain', e.g. webmasters.stackexchange.com is a subdomain of stackexchange.com. The DNS setup for a subdomain could use either an A ...


15

It will remain fr.somewhere.com unless you have rewrite conditions configured correctly: RewriteCond %{HTTP_HOST} =fr.somewhere.com RewriteRule ^(.*)$ http://www.somewhere.com/$1 [R=permanent,L] I have a cname record created for blog.legoservices.com which just points to tumblr, but all you see is blog.legoservices.com.


14

You're right that the trick is a wildcard DNS entry (indicated with asterisk) . Essentially it's a DNS entry that will match all subdomains that don't have a specific DNS entry. Then the "routing" happens on the application/website side. There is no actual DNS entry created for the subdomain, the reason that it finds a "match" when a DNS request is made, is ...


14

Indeed you can. For instance some do not realize a www. url is an actual sub-domain. So it is happening all the time. You can go to your server settings and choose your sub-domain as the main domain name or add some code to create a redirect. Many people use Apache servers for hosting websites and when you have used a domain name with traffic to it, a ...


13

2007: Here what Google's Matt Cutts has to say about sub-domains vs folders: My personal preference on subdomains vs. subdirectories is that I usually prefer the convenience of subdirectories for most of my content. A subdomain can be useful to separate out content that is completely different. Google uses subdomains for distinct products such news.google....


12

Hyphens in subdomains are just as acceptable as hyphens in domain names. One suggested drawback to hyphens in domain names is that having too many (with "too many" being more then two) it will cause your site to be put in the sandbox or face some other kind of penalty for "looking spammy". There is no definitve information on this (that I know of) so ...


11

Generally, you have to use a separate sitemap for each host (i.e., different protocol, domain, or subdomain): From the FAQ "Where do I place my Sitemap?": All URLs listed in the Sitemap must reside on the same host as the Sitemap. For instance, if the Sitemap is located at http://www.example.com/sitemap.xml, it can't include URLs from http://subdomain....


11

You can serve a different robots.txt file based on the subdomain through which the site has been accessed. One way of doing this on Apache is by internally rewriting the URL using mod_rewrite in .htaccess. Something like: RewriteEngine On RewriteCond %{HTTP_HOST} !^(www\.)?example\.com$ [NC] RewriteRule ^robots\.txt$ robots-disallow.txt [L] The above ...


10

An SSL certificate does not specify an IP, a protocol or a server. SSL cerificates are, however, tied to a specific (sub)domain. So yes, you can use the same certificate for both, even if you decide to host website and FTP server on two different locations. Some certificates even allow you to change the subdomain (so called wildcard certificates), but ...


9

i just came across this info graphic from slingshot that might be of interest : (source: seomoz.org)


9

Basically www is just a subdomain. The reason the specific site doesn't work without the www subdomain can either be a misconfigured DNS or a misconfigured configuration. You can try to do a nslookup to find out to which IP's they are assigned (to check the DNS settings are correct): Example of my own domain: nslookup responsible-disclosure.com Server: ...


8

www2 most likely means that that you have been sent to their 2nd web server directly -- possibly they do not have load balancer properly configured .. or it is configured this way on purpose, so once redirected user stays there and not hitting balancer again. Shopping.com does it all the time (at least did it in the past). It also could mean that it is ...


8

Google recently explained how to handle multilingual situations like this. Their example shows the usage of subdomains but you can use domains as well: <link rel="alternate" hreflang="en" href="http://www.company.com/" /> <link rel="alternate" hreflang="es-ES" href="http://company.es/" /> <link rel="alternate" hreflang="es-MX" href="http://...


8

uk is a TLD (top level domain). uk is the ccTLD (country code TLD) for the United Kingdom. All uk domains are controlled by Nominet. Nominet imposes additional restrictions on the registration of these domains. No-one can register a subdomain directly under the TLD uk. They must register a domain under one of the defined subdomains .co.uk, .org.uk and one or ...


7

Try this brute force script in Linux: It uses reverse DNS lookup (one name per IP), so it can't find virtual hosts (when at one IP more then one name). vi /tmp/dnsscan.sh Type i and paste this: #!/bin/bash IPPFX=$1 for i in `seq 1 255` ; do LIST="$LIST ${IPPFX}.$i" ; done for i in $LIST ; do ENTRY="`host $i`" [ $? -ne 0 ] && continue ...


7

Check out the URL removal tool in Google Webmaster Tools. I'd also 404 the pages instead of redirecting them to get them removed faster, in the future beyond robots.txt you could drop in the rel="canonical" to make sure Google knows the dev site is just a copy of the main site and is not to be indexed.


7

After receiving clarification on this from John Mueller at Google, disavowing a root domain will also disavow all other sub domains under it. For example, disavowing:- domain:example.com Will also disavow:- sub23.example.com sub4646.example.com www.example.com You can of course, disavow individual sub domains like domain:sub23.example.com though which ...


7

Google's bots will still want to request /robots.txt from your sub domain and not /robots_static.txt which would have no meaning to them. RewriteCond %{HTTP_HOST} ^www\.static\..*$ [NC] RewriteRule ^/robots\.txt$ /robots_static.txt [L] When requests for /robots.txt are made from your www.static domain the /robots_static.txt file will be served up as if it ...


7

You most certainly do not have to buy store.xyz.com as a new domain name. store.xyz.com is a part of xyz.com A domain name is made up of multiple parts www.google.com www.google.com | | | --- domain name extension | | --- domain name | --- subdomain mail.google.com mail.google.com | | | --- domain name extension | | --- ...


6

To answer the last question - if you have a domain then you can set up any subdomains you like www2.domain.com, www3.domain.com etc.


6

There's nothing explicitly wrong with it. It's just a domain. It's as cumbersome as you choose to make it. Some legitimate concerns, however, would revolve around the testing of security and certificates, etc. Since certificates are based on the TLD, it would be impossble to run tests against any web service that sits behind an SSL layer. Similarly, ...


6

Yes, SSL certificates are not tied to a specific TCP port, so this shouldn't be a problem. Only the CN of the certificate has to match the DNS host name of your server.


6

Let's try with dig: $ dig -t NS tohid.ir.tc ; <<>> DiG 9.7.3 <<>> -t NS tohid.ir.tc ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 45593 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;tohid.ir.tc. IN NS ;; AUTHORITY ...


6

Google does use domain authority to rank sites, or at least they use the Panda update to demote pages on a site-wide basis. From Google's original announcement in 2011: This update is designed to reduce rankings for low-quality sites—sites which are low-value add for users, copy content from other websites or sites that are just not very useful. At ...


6

First of all, as you're mentioned the reason to change that are cookies - there's no need - see "sub-domain cookies, sent in a parent domain request" on Stackoverflow: The leading dot in the domain value .example.com means example.com and its sub-domains. Without the leading dot, the cookie is only valid for this specific domain. Note that when ...


6

The subdomain is nothing else than a DNS record applied to the root domain. If you consider the root domain example.com, any of the following is a valid subdomain www.example.com foo.example.com foo.bar.example.com and even *.example.com *.foo.example.com Then way you create subdomains is creating a DNS record for them, regardless it's a single-level ...


6

Yes, this is definitely possible. But please note that, by convention, www.domain.com is just an alias for domain.com. So, what you describe is not at all standard and violates most users' expectations. It also runs at least some risk of search engine penalties. So, in my opinion, it is not a good idea, but yes, it's possible. Exactly how you do it depends ...


6

will browsers recognize individual files as being the same as pre-cached ones, if they are served from different subdomains? No. Two identical files served from different locations are different files as far as the browser (cache) is concerned. The URL is the key by which the file is cached by the browser. As media1, media2 etc all serve the same files, ...


6

You can remove the sub-domains in webmaster tools, but first you need to add the sub domains as seperate sites and then submit a site removal. They should be gone within a day or so. See these instructions for removing a site from google : https://support.google.com/webmasters/answer/1663427?hl=en


6

This is normal behavior. I am not sure what your question is exactly. But here goes. I am going to assume you are using Apache and host your DNS. Create the sub-domain on your server however you need. For Apache, this would be almost exactly like any other domains website. You can find the configuration files in /etc/apache2/sites-available or /etc/local/...


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