How to use alternate from addresses with Gmail on iPad or iPhone

Gmail has a neat feature that you can associate alternate from addresses with your account and then send as any of those addresses from the web interface. Unfortunately this feature is not available from the mobile web interface for iPhone or iPad. There is another way to do this using the Mail app, however.

You need to set up your Gmail account as a generic IMAP account (not using the Gmail selection). Then simply copy a comma character, and then paste that into the address field and enter all your from addresses separated by commas.

How to set up port mapping for iChat video chatting

Here's how I set up to be able to receive incoming connections for iChat for video chatting (or audio chatting or screen sharing). These instructions should work for a Time Capsule, AirPort Extreme, or AirPort Express.

Step 1 - Set up static IP addresses

The first step is to make sure that all computers on your home network have static IP addresses. The easiest way to do this is to simply have the AirPort Base Station/Time Capsule hand out the same IP address via DHCP each time. You can do this using AirPort Utility. Select your base station and go to Manual Setup. Under Internet -> DHCP -> DHCP Reservations you should add an entry for each computer.

You will need the Ethernet MAC address for each computer, which you can get in System Preferences -> Network. Go to the interface you use to connect (AirPort or Ethernet) and click Advanced... and go to the Ethernet tab. There will be an Ethernet ID listed which is a sequence of numbers and letters A-F with colons. This is what you want.

Copy and paste this into AirPort Utility, or retype it as appropriate. Then assign an IP address which is below your starting DHCP range. In my example, the dynamic range starts at 200, so anything under 200 would be fine. I use 100, 101, etc. for the statically assigned addresses.

Repeat this process for each computer on your home network that you want to use iChat video chatting/audio chatting/screen sharing with.

An alternative to this would be to use the use DHCP with manual IP address option in System Preferences -> Network. This option works best with desktop machines, since laptops may move to different networks and the static IPs you assign will likely not be valid on other AirPort networks.

Step 2 - Set up port forwarding

Now that you have the IP addresses assigned, you can redirect incoming connections to these static IP addresses as appropriate. This is done in AirPort Utility as well, under Advanced -> Port Mapping.

The port range for iChat is UDP ports 16384-16402. Starting with Mac OS X 10.5 Leopard, iChat will first try 16402, and then continue with the lower numbered ports down to 16393. Earlier versions of Mac OS X use 16384-16392 as well. If you just have one machine you can map the entire range, but if you have more than one, just assign one port to each and then the remaining ports to the computer that is most likely to be used for chatting. Here are some examples:

As you can see, you can enter both ranges of ports with a dash, or a list of ports with commas, or a combination.

Other routers

For other routers, such as LinkSys, you have to use the web configuration interface (which is usually just the router's IP address). As far as I can tell the standard LinkSys firmware does not support static DHCP reservations, but custom firmwares like HyperThibor do.

Port mapping on the LinkSys is done under Applications & Gaming -> Port Range Forward. It is not as flexible as the AirPort, so you will need one line for each continuous range of ports.

Time Capsule update

Last weekend I went ahead and completed the switchover from my old LinkSys WRT54G to the new 1GB Time Capsule as the primary router for the home network.

On the Time Capsule, I had to set up port mapping to match the previous configuration of the LinkSys. I also set up static DHCP mappings to match what was already set up. Enabled PPPoE client and DHCP server.

LinkSys changes:
- reset to defaults
- disabled WiFi
- disabled internet/WAN connection
- disabled DHCP server

I also needed to connect one of the LAN ports of the LinkSys to one of the LAN ports of the Time Capsule.

After setting all this up, I noticed the AirPort menu extra started showing the connected time for the PPPoE connection, which is a bit annoying. Luckily I was able to figure out that you turn this off from a submenu that shows up from the network name in the AirPort menu.

Another discovery I made was that with Leopard it is now possible to have multiple computers on the home network set up to do video chats. The secret was to map different incoming ports to different computers. In Leopard, iChat will try port 16402 and then continue trying lower port numbers down to 16393. Given that the Time Capsule is more flexible with port mapping, it was easy to set aside 16401 and 16400 for the laptops, while leaving all the old iChat ports for the Mac mini.

How to transfer local Time Machine backups to Time Capsule

I was able to successfully transfer the backups from our 500GB external FireWire drive to our new 1TB Time Capsule. This was not easy, so I decided to document the process for anyone who is interested.

1) Connect the external hard disk and the Time Capsule (via gigabit Ethernet) to the same computer.

2) Complete a backup to the hard disk, then turn off Time Machine while doing the conversion.

2a) If you have other computers backing up to the same hard disk, make sure those have a current backup as well before continuing.

3) Unmount the external hard disk.

4) In Disk Utility, create a new disk image from device from the external hard disk. Select the partition rather than the whole disk. I saved the image directly to the Time Capsule. This will take a long time. In my case, it took over 12 hours.

5) Unplug the external hard disk.

6) At this point, you have a .dmg with the complete contents of the external hard disk. This needs to be converted to a .sparsebundle image. This can be done using "hdiutil convert -format UDSB harddisk.dmg" on the command line. The sparse bundle will be smaller than the .dmg since free space is not copied into the sparse bundle image. In my case, I had enough space on the Time Capsule to fit both images at the same time.

6a) After the conversion was completed, I removed the .dmg file, and made another copy of the .sparsebundle. This is because I was backing up both my MacBook and Kathy's MacBook to the same external drive. In a single computer case this is not needed.

6b) Next, the two images need to be fixed up to only contain the relevant files and free space on the Time Capsule. I mounted each image and deleted the inappropriate set of backup files. This seemed to work best dragging the top level folder under Backups.backupdb to the trash and then doing rm -rf in Terminal on the files. Emptying the trash might work as well but seems to be slower.

6c) After removing unneeded files, to free up space on the Time Capsule, unmount the disk image. Then run "hdiutil compact image.sparsebundle" in Terminal. This will remove unused band files from the sparse bundle.

7) Configure Time Machine to use the Time Capsule and start a backup. Once a disk image is created, stop the backup. The image should be named <computer>__<uuid>.sparsebundle. Remove this image and rename the sparsebundle you created to match the name. Then do a backup again. You should still be doing this over Ethernet.

8) After the first backup, wireless backups should be fine.

The only other consideration is that the image size may not be correct (500GB vs. 1TB), but I don't suspect to run into that limit any time soon, and it is easy enough to resize using hdiutil.

Time Capsule arrived

We finally took the plunge and got a 1TB Time Capsule to replace our current 500GB Maxtor hard disk which has been backing up Kathy's and my MacBook since we upgraded to Leopard (around the time of my last blog post actually - yes I am lame for not blogging for so long).

So far I am liking the Time Capsule. Right now I have it set up in bridge mode and am still using the LinkSys WRT54G as the main router. Here are some of the tradeoffs between the two routers:

* Time Capsule has a built in hard disk which can be used for wireless backup
* Time Capsule supports USB printer sharing (thinking of moving the inkjet printer to be shared this way - it's currently shared by the Mac mini)
* LinkSys supports dynamic DNS which I am currently using... Time Capsule supports Back to My Mac, but doesn't seem to support dynamic DNS
* LinkSys has 4 100Mbit ports plus 1 uplink port, Time Capsule has 3 Gigabit ports and 1 uplink port
* LinkSys is 802.11g, Time Capsule is 802.11n
* Time Capsule requires a reboot for any configuration change, which takes 30 seconds or something. Config changes on the LinkSys happen much faster.

Overall, I think I should be able to totally replace the LinkSys with the Time Capsule, but the first challenge is to transfer our last 9 months of backups over to the Time Capsule. This is not as simple as you might think because the Time Capsule needs backups in sparsebundle disk image format, and the backups we have are just stored as files on the hard disk directly. I have an idea for how to get this working which is taking a while. If my plan works I will post an update on how to do it for anyone who's interested.

Apple eWaste Recycling Event this Saturday

FYI... free computer and electronics recycling at Apple this weekend.

Community Recycling Event
Saturday, April 21 - Cupertino

Apple is sponsoring a public eWaste recycling event on April 21 from 9 a.m. to 2 p.m. in the parking lot behind De Anza 3 (10500 De Anza Blvd Cupertino CA.). Tell all your friends and neighbors about the Saturday event so that they can take advantage of this free recycling opportunity.

All are invited to drop off and recycle their unwanted home computers, monitors, related computer peripherals, TVs, stereos and other small home electronics such as fax machines, printers, DVD players and cell phones (no home appliances please).

Note - Local, state and federal hazardous waste laws prohibit us from taking computer or TV monitors with cracked or broken screens and batteries of any type that are not integral to a computer system.

AppleTV as an alternative to cable

Last month when my cable bill went up again to about $55 a month (thanks Comcast), it occurred to me that it might actually be cheaper for me to just buy TV shows from iTunes... today I decided to see if this was true. It turns out that the shows Kathy and I watch would cost either $35 or $45 per season, for a grand total of $220 for seven shows for one season. As compared to $660 for standard cable for a year that's only a third of the cost... there's enough savings to pay for an AppleTV in the first year.

Also, I could just copy the video files to my iPod to watch, and there would be no commercials to skip through like I have now with the TiVo.

Unfortunately, this isn't all the TV we watch... iTunes doesn't yet have Smallville or House, and doesn't have much content from Discovery Channel or much variety of sports content, so for the immediate future we're stuck with Comcast. Still, it's an interesting option.