Before seeing what potential difficulties this creates and how to overcome them, let’s take a look at a typical home network and how it communicates with the outside world.

I use the terms home network and LAN interchangeably and for the purposes of this article they can be considered one and the same.

A Home/Local Area Network (LAN)

At the network’s centre is the router. To the right, in the diagram above, are the devices connected wirelessly or wired to the router which make-up the home network.

To identify them on the LAN, the router and each device are assigned a unique dynamic or static IP address, in this case in the range 192.168.1.1 to 192.168.1.200. These IP addresses are private and are only recognised within the LAN itself. The IP address 192.168.1.1 is usually reserved for the router.

To provide Internet access to devices on the LAN, the router is typically connected to a modem supplied by the ISP. The router is given a second IP address by the ISP to identify it externally on the Internet e.g. 123.45.67.8. However, unlike its internal private IP address which is static, the router’s external public IP address is often dynamic.

In combination with a method known as port forwarding* we need only enter the router’s external public IP address in a browser i.e. http://123.45.67.8 to remotely access the home network over the Internet.

There are two disadvantages to using the router’s external public IP address. The first, is that it can be difficult to remember. The second, and more important, is that it is most likely a dynamic IP address and will therefore change over time. Keeping track of a dynamic IP address can be difficult. Here’s where services such as those provided Dyn come in.

Using their free DynDNS Free service allows you to keep track of your router’s difficult to remember, dynamic public IP address with a more memorable static hostname.

After signing-up for an account at Dyn head over to the DynDNS Free configuration page.

DynDNS Free configuration page

1. Enter the hostname you want to use up to a maximum of 24 characters. From the drop-down menu on the right you can choose suffixes other than dyndns.info.

2. Ensure that for service type Host with IP address is selected.

3. The configuration page will show your router’s current external public IP address. Click the link to use this one or enter another valid IP address.

4. Click the Add To Cart button and follow the on-screen instructions to complete the configuration and activate your hostname. Don’t be put off by Add To Cart. Like its name suggests, DynDNS Free is free.

With the new hostname activated there’s a second step to the process.

The hostname xxxxxx.dyndns.info when entered in a browser will resolve to the router’s external public IP address as it was when the hostname was originally activated i.e. 123.45.67.8. If this is a dynamic IP address, when it changes to say 123.45.67.890 the hostname xxxxxx.dyndns.info will still resolve to the original IP address and not the new one.

To overcome this, download one of the DynDNS Updaters and install it on one of the computers on your home network. Add your Dyn account to the DynDNS updater and it will periodically check your router’s external public IP address. If it detects that the IP address has changed, it sends the new IP address to the hostname in your Dyn account.

Using OS X Lion 10.7.1, I’ll describe two ways of assigning a static IP address to a computer on a local network.

Using DHCP With a Manual Address

The first method uses the Network preference pane in System Preferences.

Open System Preferences and click Network.

Network preference pane in System Preferences

1. Before continuing, you may need to authenticate by clicking the lock icon.

2. The current services are listed on the left of the Network preference pane. I have a wireless network so I select the active Wi-Fi service.

3. To continue click Advanced…

TCP/IP tab showing computer’s dynamically assigned IP address using DHCP

4. On the TCP/IP tab the computer is shown as having an IP Address of 192.168.1.99 dynamically assigned using DHCP.

Assigning a static IP address using DHCP with manual address

5. From the drop-down menu select Using DHCP with manual address. This allows a static IP Address to be assigned to the computer. Here, I’ve entered 192.168.1.2.

6.Click OK to return to the Network preference pane.

Network preference pane before changes are applied

7. The all important step I sometimes forget. Remember to click Apply to save the changes. The computer now has a static IP address on the local network.

DHCP Reservations

The second method uses a router to reserve a static IP address for an individual computer. The method described here uses an Airport Extreme 802.11n wireless router.

First, we need to find the computer’s unique MAC (Media Access Control) address.

Open System Preferences and click Network.

Network preference pane in System Preferences

1. Select the currently active service listed on the left of the Network preference pane.

2. To continue click Advanced…

Hardware tab showing the computer’s MAC Address

3. The Hardware tab shows the computer’s MAC (Media Access Control) address in the format xx:xx:xx:xx:xx:xx. Make a note of it for later.

4. To return to the Network preference pane click Cancel.

I’ll be using AirPort Utility to configure the Airport Extreme.

Open AirPort Utility located in Applications > Utilities.

Initial screen of AirPort Utility

5. Click on Manual Setup to continue.

DHCP tab showing DHCP reservations

6. Click the Internet icon.

7. On the DHCP tab click + to add a DHCP reservation.

Initial screen of the DHCP Reservation Setup Assistant

8. Add a description for the reservation.

9. Ensure that MAC Address is selected to reserve the IP address.

10. Click Continue to go to the next screen of DHCP Reservation Setup Assistant.

Final screen of the DHCP Reservation Setup Assistant

11. Enter the computer’s MAC address obtained earlier in the format xx:xx:xx:xx:xx:xx.

12. Enter an IP address you want assigned to the computer. Note that it’s only possible to change the fourth and final series of numbers.

13. Click Done to return to the DHCP tab.

DHCP tab before applying updates

14. Enter more IP addresses for other computers on the local network if desired. Then Click Update to apply the changes and assign the computer(s) a static IP address.

To put an open application into full-screen mode, simply click the arrows in the top-right corner of the application’s window.

However, re-opening an application in full-screen appears not so straight forward.

My understanding is that if you want an application to re-open in full-screen mode you mustn’t quit the full-screen application using command-Q. Instead, you need to navigate to the Desktop, control-click the application icon in the Dock and click Quit. It appears also that you need to do this every time you want the application to re-open in full-screen mode.

However, this seems a little inconsistent. Take Mail for example.

Open Mail in non full-screen mode and open, say, the Activity window (Window > Activity). Now put Mail into full-screen mode and launch Mission Control. You’ll see that as a full-screen application Mail occupies its own space. Mail’s Activity window, however, is shown on the Desktop.

Quit Mail while in full-screen using the method described above and you’d expect Mail to re-open full-screen. It doesn’t. Why? I suspect it has something to do with the Mail’s Activity window.

So, close the Activity window first before putting Mail into full-screen mode. Now quit Mail using its Dock icon. Open Mail and it’s full-screen.

I’ve experienced the same problem when Mail’s Preferences window is open, but not with Mail’s Photo Browser nor Address Panel windows. The same is true of Safari with either the Preferences or Activity windows open. iTunes however seems to suffer no such problem. It re-opens in full-screen regardless of which windows were open. Odd.

Whether this is expected behaviour or a bug, the way to have a fair chance of applications re-opening in full-screen mode is to close any additional application windows first.

I’ve been using site statistics provided WordPress.com for some time. The popular posts widgets in the sidebar and on single post pages rely on these statistics to display this site’s most viewed posts and pages.

I’d been using the WordPress.com Stats plugin until March when inexplicably it appeared to no longer work. At that time, I switched to the Jetpack plugin which includes the former WordPress.com Stats functionality. I assumed the Jetpack plugin had replaced the WordPress.com Stats plugin and that the latter was no longer available.

In searching for an answer to the broken page navigation I found the WordPress.com Stats plugin still available for download. It was worth a try, so I deleted the Jetpack plugin and installed the WordPress.com Stats plugin. After a frustrating afternoon trying to get the plugin to connect to the WordPress.com servers this site’s stats are now being provided courtesy of the WordPress.com Stats plugin. More importantly, page navigation is once again working as it should.

This site uses custom permalinks, /%category%/%postname%/, but when navigating pages the URLs are incorrect. Instead of http://domain/page/2 they’re being re-written as http://domain/2. Consequently, I’m getting 404 Not Found errors.

Why blame the Jetpack plugin? By accident, I deactivated the Jetpack plugin and noticed that page navigation was working. Interestingly, the issue arises only if I’m not logged-in as admin.

I’ve posted more detail over on the WordPress.com forums in the hope someone has an answer.

Until I’ve managed to fix this, all of my posts, a laughable 30 in total, will appear on one long page.

This and many other add-ons have been incompatible with Firefox since the release of Firefox 4 back in March. One of the work-a-rounds was to disable add-on compatibility checking in Firefox.

To get incompatible add-ons working in Firefox 4 I’d followed the instructions here replacing the preference name extensions.checkCompatibility.3.6 with extensions.checkCompatibility.4.0

Unfortunately, with the release of Firefox 5 this week, just 3 months after the release of Firefox 4, many add-ons are once again not working. It’s easy enough to fix though. Just follow the instructions in the link above this time replacing the preference name extensions.checkCompatibility.3.6 with extensions.checkCompatibility.5.0

Let’s assume we have two Macs. An iMac that I’ll call Computer A and a MacBook that I’ll refer to as Computer B. Computer A contains the latest, up-to-date Address Book and iCal data.

Address Book

OS X stores Address Book data in the AddressBook folder contained in the folder ~/Library/Application Support/.

Configuring Address Book Sync on Computer A

The first thing to do is to move this AddressBook folder on Computer A to the Dropbox folder.

On Computer A, quit Address Book and open the Terminal application. Type the following command and press return.

 
cd ~/Library/Application\ Support
 

This changes the current directory to that containing the AddressBook folder.

Next type the following command adding a space at the end. Don’t press return yet.

 
mv AddressBook
 

Now locate your Dropbox folder in the Finder and drag it to the Terminal window. This copies the full path to your Dropbox folder into the Terminal command like so:

 
mv AddressBook /Volumes/Data/Users/steve/Dropbox
 

Press return to move the AddressBook to the Dropbox folder.

Next we need to ensure that Address Book can find its data in the Dropbox folder as it expects it to be located in the ~/Library/Application Support/ folder. To do this, create a symbolic link named AddressBook in the ~/Library/Application Support/ folder which points to the ~/Dropbox/AddressBook/ folder.

To create the symbolic we must use the ln command in Terminal. This is not the same as creating an alias in the Finder using drag-and-drop while holding down the option and command keys. The latter should not be used as Address Book will be unable to find its data in the Dropbox folder and will create a new, empty address book.

 
ln -s /Volumes/Data/Users/steve/Dropbox/AddressBook /Volumes/Data/Users/steve/Library/Application\ Support
 

If we navigate to the ~/Library/Application Support/ folder in the Finder we’ll see what appears to be a folder named AddressBook. This is in fact the symbolic link we created in Terminal.

If we click on this symbolic link we’ll see that it’s actually pointing to the ~/Dropbox/AddressBook/ folder.

Open Address Book and confirm that the data is as it should be.

Next we’ll configure Address Book on Computer B.

Configuring Address Book Sync on Computer B

On Computer B locate the Dropbox folder in the Finder. You’ll see that it contains the synced AddressBook folder.

However, the Address Book on Computer B is currently using data in the ~/Library/Application Support/AddressBook/ folder.

First, we need to delete the ~/Library/Application Support/AddressBook folder. So, simply drag it to the Trash.

We’re now ready to create a symbolic link on Computer B named AddressBook in the ~/Library/Application Support/ folder which points to the ~/Dropbox/AddressBook/ folder.

 
ln -s /Users/steve/Dropbox/AddressBook /Users/steve/Library/Application\ Support
 

The Address Books on Computer A and Computer B should now remain in sync.

iCal

Apart from the location of the calendar data, the method for syncing iCal calendars is identical to that of Address Book. OS X stores iCal calendar data in the~/Library/Calendars/ folder. For continuity, I’ll detail the entire process in its entirety.

Configuring iCal Sync on Computer A

The first thing to do is to move this Calendars folder on Computer A to the Dropbox folder.

On Computer A, quit iCal and open the Terminal application. Type the following command and press return.

 
cd ~/Library
 

This changes the current directory to that containing the Calendars folder.

Next type the following command adding a space at the end. Don’t press return yet.

 
mv Calendars
 

Now locate your Dropbox folder in the Finder and drag it to the Terminal window. This copies the full path to your Dropbox folder into the Terminal command like so:

 
mv Calendars /Volumes/Data/Users/steve/Dropbox
 

Press return to move the Calendars to the Dropbox folder.

Next we need to ensure that iCal can find its data in the Dropbox folder as it expects it to be located in the ~/Library/ folder. To do this, create a symbolic link named Calendars in the ~/Library/ folder which points to the ~/Dropbox/Calendars/ folder.

To create the symbolic we must use the ln command in Terminal. This is not the same as creating an alias in the Finder using drag-and-drop while holding down the option and command keys. The latter should not be used as iCal will be unable to find its data in the Dropbox folder and will create new, empty calendars.

 
ln -s /Volumes/Data/Users/steve/Dropbox/Calendars /Volumes/Data/Users/steve/Library
 

If we navigate to the ~/Library/ folder in the Finder we’ll see what appears to be a folder named Calendars. This is in fact the symbolic link we created in Terminal.

If we click on this symbolic link we’ll see that it’s actually pointing to the ~/Dropbox/Calendars/ folder.

Open iCal and confirm that the data is as it should be.

Next we’ll configure iCal on Computer B.

Configuring iCal Sync on Computer B

On Computer B locate the Dropbox folder in the Finder. You’ll see that it contains the synced Calendars folder.

However, iCal on Computer B is currently using data in the ~/Library/Calendars/ folder.

First, we need to delete the ~/Library/Calendars/ folder. So, simply drag it to the Trash.

We’re now ready to create a symbolic link on Computer B named Calendars in the ~/Library/ folder which points to the ~/Dropbox/Calendars/ folder.

 
ln -s /Users/steve/Dropbox/Calendars /Users/steve/Library/
 

Your iCal calendars on Computer A and Computer B should now remain in sync.

With that in mind here are a few ways to enter file/folder paths in Terminal.

For these examples I’m going to change the current directory from /Volumes/Snow Leopard to /Volumes/Data/Users/steve/Library/Application Support using the cd command.

The first method is to enclose the file/folder path in single or double quotes:

 
Steves-iMac:Snow Leopard steve$ cd '/Volumes/Data/Users/steve/Library/Application Support'
Steves-iMac:Application Support steve$
 

The second is to escape any space with a forward slash (\). The forward slash should be placed immediately before each space:

 
Steves-iMac:Snow Leopard steve$ cd /Volumes/Data/Users/steve/Library/Application\ Support
Steves-iMac:Application Support steve$
 

If the file or folder exists in the current user’s home folder we can use ~/ as shorthand to denote the user’s home folder:

 
Steves-iMac:Snow Leopard steve$ cd ~/Library/Application\ Support
Steves-iMac:Application Support steve$
 

If we want to use quotes, the opening quote must come after the ~/ shorthand:

 
Steves-iMac:Snow Leopard steve$ cd ~/'Library/Application Support'
Steves-iMac:Application Support steve$
 

The one I use most though, because it is perhaps the easiest, is to locate the file or folder in the Finder and drag it to an open Terminal window:

The full file/folder path is copied at the Terminal window’s current cursor position:

At home when my iPhone was using the wi-fi network, mail was being sent without issue. Away from home and using the 3G network I couldn’t send mail from this one account. At first I thought the problem was down to my carrier’s (Softbank Japan) 3G network. But as I could send email from other accounts on my iPhone over 3G this didn’t make sense.

By chance I was looking at the mail account settings on my Mac and noticed that the mail account I was having issues with on the iPhone had its associated SMTP (outgoing mail server) port set to 80.

As I sync my mail settings via iTunes to the iPhone this same port would be used there.

The other mail accounts had SMTP ports set to 587 or using SSL on port 465.

I can’t recall why this one mail account was configured to send mail using a non-standard SMTP port, but the ISP that provides my home internet must be allowing SMTP traffic over port 80 as both my Mac and iPhone could send mail using this port when connected to my home wi-fi.

However, the same wasn’t true of my 3G carrier. They were apparently blocking SMTP traffic over port 80.

The fix was simple. I changed the SMTP port to 465 using SSL for the offending mail account on my Mac and synced the changed mail settings to my iPhone.

Sending mail from my iPhone using the 3G network now works without issue.

To exclude my Contact page from the search results I added this code block to my function library.

// Exclude posts/pages from search results
function exclude_from_search($query) {
	if ($query->is_search) {
		$excluded = array(
			321,		// Sitemap
			523			// Contact Page
		);
		$query->set('post__not_in', $excluded);
	}
	return $query;
}

add_filter('pre_get_posts','exclude_from_search');

If you don’t currently use a function library you can read about setting one up here.

From the point of view of customising this function to meet your own needs, the important piece of code is the declaration of the $excluded array beginning on line 4. This array contains the IDs of the posts or pages you want to exclude.

An easy way to find post or page IDs is to select Posts or Pages from the WordPress Admin panel and place the mouse cursor over the appropriate post/page title. Your browser’s status bar should show a string similar to ../post.php?post=523&action=edit where the post/page ID is 523.

Note that the exclude_from_search() function is associated with the pre_get_posts hook using add_filter(). When this hook executes it passes the current query object to the exclude_from_search() function.