macosxhints.com network tips

Automatically start Internet Sharing via LaunchDaemon

Wed, 11 Nov 2009 07:30:00 -0800

In the past, people have submitted hints on how to get their Macs to start internet sharing automatically at boot. All of them are either editing files in hidden directories or creating a StartupItem to do the task. Most people may not want to edit files that are for the system, and Leopard and later versions of OS X use LaunchDaemons, not StartupItems to run scripts or executables at boot.

I created a LaunchDaemon plist based on the composition of the iStat Server's LaunchDaemon plist to run the InternetSharing executable automatically at boot. Here's what it looks like:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
&...

10.6: A fix for failure to connect to new wireless networks

Wed, 04 Nov 2009 07:30:23 -0800

After upgrading from 10.5.8 to 10.6.1 on my MacBook Pro, I was unable to connect to wireless networks unless I had already connected to them running under 10.5.8. Snow Leopard would "see" the new networks, but could not connect to them.

The Genius Bar at the Apple Store helped me solve the problem. We opened Library » Preferences » SystemConfiguration, and trashed the entire contents of that folder. We also deleted all locations in System Preferences » Network, and recreated the location Automatic. Finally, we rebooted.

So far, I have been able to connect to all wireless networks that I want to using OS X 10.6.1.

Set Screen Sharing image quality via Terminal

Tue, 27 Oct 2009 07:30:05 -0700

I have to manage several Macs in a lot of locations and I was very confortable with the Bonjour discovery, saved connections, and hidden features of the 10.5 Screen Sharing app. Alas, with the release of 10.6, they have gone -- Apple wants to sell Apple Remote Desktop.

I have found that using this command in Terminal...

defaults write com.apple.ScreenSharing controlObserveQuality n

...changes the quality of the connection's display, based on the value of n:

1 = black and white
2 = grayscale
3 = 8-bit color
4 = 16-bit color
5 = full color

I also set up shortcuts using the vnc://192.168.0.1 URL convention in Safari, as discussed in this hint and comments. I save all my connection shortcuts in a folder, and put that folder in my Dock. I now have a Saved Conne...

Enable anonymous FTP in 10.5 and 10.6

Tue, 27 Oct 2009 07:30:02 -0700

To enable anonymous FTP in Snow Leopard (and probably Leopard as well), just execute the following commands in Terminal:

$ sudo dscl . -create /Users/ftp
$ sudo dscl . -create /Users/ftp NFSHomeDirectory /path/to/ftp/folder

Replace /path/to/ftp/folder with the path to the directory that the guest account will have access to. To disable anonymous access, use this command:

$ sudo dscl . -delete /Users/ftp

You may have to restart the FTP daemon by stopping File Sharing and starting it again in System Preferences. Although I didn't test it in Leopard, I see no reason why it shouldn't work there as well.

[robg adds: I haven't tested this one.]

Delete file from network volume without warning dialog

Mon, 19 Oct 2009 07:30:05 -0700

Whenever I delete a file from a network volume, I'm warned: 'The item "File name" will be deleted immediately. Are you sure you want to continue?' with Cancel or Delete as options. The Cancel button is always the default option. If you really want to delete the file, you need to use the mouse to select the non-default Delete button. Since I am always sure that I really want to delete this file, I'm a little annoyed by always having to use the mouse after typing Command-Backspace (the Move to Trash shortcut). After all, I am using a shortcut because I want to avoid using the mouse.

If you press Command-Option-Delete, however, the networked file will be deleted immediately, without any warning at all. As with the normal method of deleting a networked file, this deletes the file immediately.

[robg adds: You can avoid the mouse with the Command-Delete method by pressing Tab then Space after the dialog appears. If you look at the File menu with the Option ...

10.6: Switch between two wireless networks in one location

Wed, 07 Oct 2009 07:30:03 -0700

For one reason or another, I have two wireless networks available to me to use in one location. One is DHCP enabled, while the other requires manual setup.

The obvious solution for switching between these networks is to use the Locations feature in Networking to save two profiles, and then use the drop-down Location menu to switch between them. However, I have found that because my MacBook has the logins for both networks saved, it does not switch the wireless network, just the settings. Once you mix DHCP with manual settings, it just fails to work, and requires more intervention.

My solution (admittedly inelegant, but I don't know how to implement a better way), was to create a shell script that will switch the locations, and power cycle the AirPort card (which means it picks up the 'preferred' network). This is then set as a Service using Automator, and assigned a key...

Safely and socially share a wireless network

Wed, 16 Sep 2009 07:30:00 -0700

This is not really Mac-specific, but still a good idea. I like two things: sharing and encryption. But you can't have both with wi-fi. Either you share it or you encrypt the OTA transmissions with WPA.

My compromise, which works for anyone in an apartment building is simple. Name your network like this:

Bring beer to [apt number] for Password

It's a nice way to get to know your neighbors, gets you free beer (pro tip: you can substitute other items for beer), and lets you be generous with your wi-fi while giving you some added level of security from the WPA encryption.

[robg adds: I can think of both upsides and downsides to this idea; it will be interesting to read what others think of it.]

10.6: Snow Leopard IPSec VPN and Cisco VPN client

Tue, 15 Sep 2009 07:30:01 -0700

If you previously used the Cisco VPN Client and want to use the native Snow Leopard client, you need to un-install all of the Cisco configs, kernel extensions, etc. To do this, just run sudo /usr/local/bin/vpn_uninstall in Terminal.

If you don't, the menu bar VPN control won't work, and will be very sluggish to click around in. The same goes for the Verizon Access Manager and the CDMA 3G built-in drivers.

10.6: Use 'special' keys in screen sharing

Wed, 09 Sep 2009 07:30:08 -0700

I'm not sure if it's well-known, but Screen Sharing in Snow Leopard now supports all keyboard commands, including Command-Tab, Command-Space, and Command-Option-Escape. In 10.5, these keystrokes were sent to the local machine; in 10.6, they go to the screen sharing session.

[robg adds: In 10.6, whether you're sharing the screen of a 10.5 or 10.6 Mac, basically all keystrokes are sent to the remote machine, including kyes for Expos� and Dashboard -- if you've programmed separate keys beyond the hardwired keys -- F9 for Expos�'s All Windows mode, for instance, gets sent from my MBP to my Mac Pro, but F3 (the hardwired Expos� key) does not. To send the keys locally, you'll need to click on a visible window (or the Desktop) behind the Screen Sharing session.]

10.6: Add NFS Mounts using Disk Utility

Wed, 02 Sep 2009 07:30:04 -0700

NFS mounts are now added using Disk Utility. To add a Linux-hosted NFS share on my network, I did the following

Start Disk Utility
Select NFS Mounts from the File menu
Click the plus sign in the lower left corner
Enter in your remote NFS URL info as described
Enter the mount point. If you add it to /Network, then it will show up in the Shared section of Finder, in an entry called All.
If you're using secure ports on your server, then click the Advanced option and enter -P
Click Verify
Save your settings

The NFS mount is now available.

10.6: Save Cisco IPSec password in the Keychain

Fri, 28 Aug 2009 07:30:00 -0700

Mac OS X Snow Leopard adds support for Cisco IPSec VPN connections -- that is, plain IPSec with XAuth authentication and mode_cfg.

That makes it two layers of authentication: first, Machine Authentication with a password (Shared Secret) or an X509 certificate. Then a traditional username-password pair for XAuth, both of which you can enter and save in the Account Name and Password fields respectively when you set up the connection. Trouble is, even though you entered your password and it is apparently saved in the keychain properly, Mac OS X keeps nagging you to manually enter the password every time you connect. Turns out this is a just bug with a simple fix.

Open the Keychain Access Application, select the System keychain and find your saved XAuth password entry in the list. Its Kind field will say IPSec XAuth Password. Open it, then on the Access Control tab...

A script to automtically enable and disable the firewall

Wed, 22 Jul 2009 07:30:00 -0700

This hints allows your firewall to automatically turn on or off based upon which network you are on. A LaunchAgent watches resolv.conf in order to detect when there are changes in the network. Save the following in /Library/LaunchAgents:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>KeepAlive</key>
  <false/>
  <key>Label</key>
  <string>com.yourcompany.autofirewall</string>
  <key>ProgramArguments</key>
  <array>
    <string>/Library/Scripts/yourcompany/autofirewall.sh</string>
  </array>
  <key>RunAtLoad</key>
  <false/>
  <key>WatchPat...



How to help AirPort recall passwords
Tue, 07 Jul 2009 07:30:03 -0700
The following situation describes a common problem people seem to be having with AirPort reconnections. While most people do not seem to have these symptoms, many, including me, have experienced the following problem with AirPort:



You connect to a password-protected wireless network. In the process, you check the box requesting that AirPort remember the network and password. When you start up your computer, or when you restart your AirPort card, AirPort connects to your preferred network with no difficulty. Hooray, AirPort remembers the password!



However, if you get disconnected and try to reconnect without restarting AirPort or rebooting, AirPort prompts you for a password. For some reason, AirPort forgets that it already has the password. If you try to switch networks on-the-fly, the same thing happens -- AirPort seems to forget that it already has the password.



What's really going on here is that on-the-fly network switches utilize password and permissi...


Make SMB shares appear in Devices section of Finder sidebar
Thu, 02 Jul 2009 07:30:01 -0700
It was driving me nuts that SMB shares from my Windows server would not reappear under DEVICES in the sidebar. However, I then figured out that I can do this:

Open System Preferences » Network
Click the network interface you use for the shares
Click on the Advanced button at lower right
Click on WINS tab, and manually enter the workgroup name of the server
Click the '+' under the WINS Servers list
Enter the IP of the server (you are using static IP on your server, right?)
Click OK, Apply, etc. until you're done

The next time I dragged a mounted share to Devices, it then showed up there automatically after the next unmount/mount. My shares seem to mount much faster now, as well. Now if only I could find a way to increase the transfer speed...sigh.


One way to quickly connect to a Cisco VPN
Mon, 29 Jun 2009 07:30:00 -0700
In February, this hint explainted how to install vpnc as a replacement for the Cisco VPN client. I finally got it working with a little tweaking and divergence from the original instructions, based in part on follow-up comments.



But what I really wanted was to have my VPN as easy (or easier) to activate than using the (otherwise awful) Cisco application: largely because I use my company's VPN in conjunction with 3G mobile broadband, which has a habit of dropping connection when my commuter train goes through a tunnel, requiring regular reconnection!



I tried using Shimo and vpntool with no success, and finally got it working using the following solution...

Install vpnc using Fink (as per earlshango's suggestion in the original comments). You need to add the 'unstable' repository when you configure Fink, since vp...


Mutihoming with one Ethernet interface
Mon, 08 Jun 2009 07:30:00 -0700
Like many small businesses we have taken advantage of the 'free' DSL services offered as part of an existing mobile phone contract. In this case we use Orange for mobile service (we're based in the UK) and they offer 2 Mbit internet with a wireless router for no extra if you have at least one pay monthly account. I thought that it would be a useful addition to our network for testing and backup, especially as it is from a different ISP and delivered over a physically separate landline from our business internet.



The wireless router arrived yesterday and the DSL activation happened on time so that the line came up first time when I plugged the line into the router. I'd heard a few horror stories about Orange's support for Macs so I was pleasantly surprised when I popped the install CD into my MacBook and it came with full OSX installation instructions. 5 minutes later I was surfing on the internet via my shiny new Orange broadband.



Now that we had two internet acces...


Easily stream audio and video between two Macs
Mon, 04 May 2009 07:30:02 -0700
Problem: I wanted to watch Live TV from a Mac upstairs in a room downstairs with another Mac. Hardware: Elgato EyeTV EZ, AirPort, and two Macs. There are some streaming solutions out there (VLC, CyTV, EyeTV, etc.), but they either do not support my hardware, or seem complicated, or stream re-encoded video only (no live TV, of course).



But there's a really simple solution: OS X 10.5's Screen Sharing, which works flawlessly and 'streams' all of my Mac's contents. The only pity is that it doesn't send the audio as well. Enter Soundfly -- it streams audio in good quality (various settings available). Now with Screen Sharing and Soundfly running, I can watch live TV and movies downstairs. Because I also can remotely control the Mac upstairs, it's also possible to start and stop recordings, and more. This works quite well.



Note: As far as I can tell, Soundfly simply redirects the audio from one Mac to the other -- the ...


A fix for failed Airport Extreme-N access control list updates
Wed, 29 Apr 2009 07:30:03 -0700
I have confirmed this bug at two sites using seven different AirPort Base Stations. I thought I had updated the Access Control List (ACL) on multiple Base Stations to allow several new computers and devices on the networks. Afterwards, however, users claimed trouble accessing in some locations -- that turned out to be true anywhere there was an AirPort Extreme-N Base Station; the older AirPort-Gs worked fine. Here's the mix of gear I was using to confirm this issue:

Airport Utility v5.4.1
Airport Extreme-N Firmware v7.4.1
Airport Extreme-N Base Station (both 10/100 and 10/100/1000 versions) with an existing ACL
PowerMac G5 - Mac OS 10.5.6 Server 
PowerMac G4 - Mac OS 10.4.11

The Problem: Using Airport Utility v5.4.1, importing an Access Control List (File » (Option key) Import Access Controls) shows the updated ACL in the Access tab list.  When the Base Station is updated and the configuration redisplayed, none of the new...


10.5: Back to My Mac fails to start due to incorrect time
Mon, 27 Apr 2009 07:30:03 -0700
For some time now, Back to My Mac (BTMM) has failed to start on my Mac Mini at home, although it worked fine on my MacBook Pro from the same network. After trying many many different things and following a number of hints, I remembered reading that BTMM uses IPsec. IPsec tunnels require endpoints to have their clocks synced, or at least to be set to times that are relatively close to one another. 



I noticed the time on my Mac Mini differed from that of my MacBook Pro by about 10 minutes, and was failing to update its local time via time.apple.com (on the Date & Time tab of the Date & Time System Preferences panel). I switched it to time.asia.apple.com, the clock updated, and BTMM connected immediately after I clicked Start in the Mobile Me System Preferences panel.



See the comments for some recom...


Log in to a single SMB share with multiple user names
Thu, 09 Apr 2009 07:30:00 -0700
I was having trouble connecting to multiple directories on a single SMB share in Leopard, where the directories had different logins. If I was logged into one directory as one user, then the "Connect to Server..." option in the Finder would default to that user for all directories on the same share and error out. I found a workaround for this.



With one directory already mounted under the first user login, select  Go » Connect to Server. Type in your share name with the user before the drive name:

smb://2ndusername@drivename/2ndDirectory

Finder will then prompt you for a password, and mount the directory as a separate network drive. This should also work for AFP shares, though I haven't tried it.