How to clear OS X DNS cache

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You may occasionally get into a situation where the DNS on your Mac needs to be flushed from the system in order for a new server or some other DNS address change.

A DNS cache contains entries that translate Internet domain names *such as “compnetworking.about.com”) to IP addresses. The Internet’s Domain Name System (DNS) involves caching on both Internet DNS servers and on the client computers that contact DNS servers. These caches provide an efficient way for DNS to efficiently keep the Internet synchronized as the IP addresses of some servers change and as new servers come online.

OS X Yosemite have “new systems” to manage DNS which is

  1. MDNS Cache (Multicast DNS)
  2. UDNS Cache (Unicast DNS)

This post show how we clear the cache. Open the terminal and run this command

Clear MDNS Cache

sudo discoveryutil mdnsflushcache

Hit return and enter the admin password when requested.

Clear UDNS Cache

sudo discoveryutil udnsflushcaches

Again, hit return and enter the admin password when requested.

Flush and Reset All DNS Caches

sudo discoveryutil mdnsflushcache;sudo discoveryutil udnsflushcaches;say flushed

UPDATE: 

If your Mac is on 10.10.4, you need to use this command

sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder;say cache flushed

How to map .html to asp.dll (IIS7 & IIS 7.5)

There is some bug on IIS 7.5 where the setting on IIS handler mapping not able to function well when it need to edit the existing hander to  use other executable module.  It not a known bug but it do happen based on my testing.

IIS7.5

But we can try do the setting on backend.

CAUTION: Make Sure you have backup all the copy of the file that you edit.

1) go into the C:\Windows\System32\inetsrv\config directory and edit the fileapplicationHost.config (you will need to do this in administrator mode, or do it from a different computer networking over to that server, otherwise Windows will protect that file and won’t allow you to change it.)

2) Scroll all the way to the bottom and look for the section that corresponds to your web site <location path=”Your Web Site”>

3) Change/edit the code block to add in the HANDLERS and HTM map below

<location path="Your Web Site"> 
<system.webServer>
<asp appAllowClientDebug="true" scriptErrorSentToBrowser="true" /> 
<handlers> 
<add name="htm" path="*.htm" verb="*" modules="IsapiModule" scriptProcessor="%windir%\system32\inetsrv\asp.dll" resourceType="File" /> 
</handlers> 
</system.webServer> 
</location>

4) Save it and restart IIS. Bingo.

Googlebot Simulator

What is Google Bot?

Googlebot is Google’s web crawling bot (sometimes also called a “spider”). Crawling is the process by which Googlebot discovers new and updated pages to be added to the Google index.

It is very important to allow google bot to access your site so that your site ranking on search engine.

Here is the tools to identify if your site is reachable by Google bot.

ihatetheory

Just insert your domain name and click on the Run Tool >> , the result will come out. If your site is unreachable by google bot, it will return error.

 

 

Diagram tool: CACOO

cacoo03

On the daily work, we might need to draw out lots of diagram, such as flow chart, network, organation chart.

Usually we can use Visio, Excel to assit on this. But that do have a lot of online tools today allow you to do it online without any installation.

The tools that I recommend is CACOO , it offer range of diagram to select.

cacoo01

Another cool things that I always use is, share. You can share the diagram among your friend.

cacoo02

So if you looking the simple diagram drawing tools, you can consider this. You might use this link to register the account, I can earn some extra sheets.

 

Microsoft command-line FTP client

ftp-click

To connect to another computer using FTP at the MS-DOS prompt, command line, type FTP and press enter.

 

open ftp.domain.com

 

Insert Username and Password.

Then you will able to use the command as below.

! - Runs the specified command on the local computer
? - Displays descriptions for ftp commands
append - Appends a local file to a file on the remote computer
ascii - Sets the file transfer type to ASCII, the default
bell - Toggles a bell to ring after each file transfer command is completed (default = OFF)
binary - Sets the file transfer type to binary
bye - Ends the FTP session and exits ftp
cd - Changes the working directory on the remote computer
close - Ends the FTP session and returns to the command interpreter
debug - Toggles debugging (default = OFF)
delete - Deletes a single file on a remote computer
dir - Displays a list of a remote directory's files and subdirectories
disconnect - Disconnects from the remote computer, retaining the ftp prompt
get - Copies a single remote file to the local computer
glob - Toggles filename globbing (wildcard characters) (default = ON)
hash - Toggles hash-sign (#) printing for each data block transferred (default = OFF)
help - Displays descriptions for ftp commands
lcd - Changes the working directory on the local computer
literal - Sends arguments, verbatim, to the remote FTP server
ls - Displays an abbreviated list of a remote directory's files and subdirectories
mdelete - Deletes one or more files on a remote computer
mdir - Displays a list of a remote directory's files and subdirectories
mget - Copies one or more remote files to the local computer
mkdir - Creates a remote directory
mls - Displays an abbreviated list of a remote directory's files and subdirectories
mput - Copies one or more local files to the remote computer
open - Connects to the specified FTP server
prompt - Toggles prompting (default = ON)
put - Copies a single local file to the remote computer
pwd - Displays the current directory on the remote computer (literally, "print working directory")
quit - Ends the FTP session with the remote computer and exits ftp (same as "bye")
quote - Sends arguments, verbatim, to the remote FTP server (same as "literal")
recv - Copies a remote file to the local computer
remotehelp - Displays help for remote commands
rename - Renames remote files
rmdir - Deletes a remote directory
send - Copies a local file to the remote computer (same as "put")
status - Displays the current status of FTP connections
trace - Toggles packet tracing (default = OFF)
type - Sets or displays the file transfer type (default = ASCII)
user - Specifes a user to the remote computer
verbose - Toggles verbose mode (default = ON)

No Theory, just solution!!!