dns
dns prefetch / pre-resolve hostname – how effective?
In the first case, DNS pre-fetching will not help as you are loading the same resource on each page. The resource should be cached on subsequent requests, so pre-fetching the dns record won’t have any effect. In the second case, simply removing and adding the link element is not sufficient to test the effect of … Read more
Automatic cookie single sign on on multiple domains – like google
The cookies are set on specific domains. Ex: setcookie(name,value,expire,path,domain) When you log in on gmail, before “mail.google.com”, you have been redirected to “accounts.google.com” then to “mail.google.com” so the cookies are on “accounts.google.com” too. In this case, the domain is “accounts.google.com” and the path is “/” (the home path). When you request “www.youtube.com” then you click … Read more
dig returns SERVFAIL but +trace works
dig +trace follows the whole chain from the beginning – it queries root servers, then .info servers then your namservers. Thus it avoids any caching resolvers, and also avoids propagation issues. dig +notrace (the default) queries your default DNS resolver (on Linux, whatever specified in /etc/resolv.conf). There’s some problem with that resolver – maybe it’s … Read more
Rails – How to Redirect from http://example.com to https://www.example.com
As an extension to user2100689’s answer, in Rails 3+ you can use config.force_ssl = true in config/environments/production.rb The line can just be uncommented as follows # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies. config.force_ssl = true
difference between a DNS zone and DNS domain [closed]
As explained here: Domain name servers store information about part of the domain name space called a zone. The name server is authoritative for a particular zone. A single name server can be authoritative for many zones. Understanding the difference between a zone and a domain is sometimes confusing. A zone is simply a portion … Read more
Domain doesn’t work without `www`
All you need is to add the following code to your root .htaccess file: RewriteEngine on RewriteCond %{HTTP_HOST} !^www\. RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]
Switch firefox to use a different DNS than what is in the windows.host file
I use this to override system’s DNS with localserver in about:config change this value: network.dns.forceResolve network.dns.ipv4OnlyDomains network.dns.localDomains with IP address of local DNS server (for exsample 192.168.1.88) Sorry for my english