Netflix not sending DVDs reliably

Netflix has been really annoying lately.  On the surface, they're
being useful -- sending us DVDs before we've sent back the old DVDs.
But in practice, we're sometimes not getting DVDs we're supposed to
get.

The problem is that we have multiple DVD queues, one for items that my
wife Catie picks, one for items that I pick.  We have one DVD
allocated to Catie's list, and two to mine, since we both watch
through mine a lot faster.  Catie sometimes doesn't watch her DVDs for
a while.  When Netflix sends extra DVDs to one queue, they sometimes
don't send DVDs to the other queue until the extras are sent back.  So
if Catie has an extra DVD on her queue and doesn't watch it, then I
might not get one of my DVDs.  And if she has two extras, then I can
stop getting DVDs altogether.  This isn't how the DVD allocations are
supposed to work.  It's infuriating.

I've contacted netflix a couple of times to complain about this, but
the customer service folks don't have the ability to do anything about
it.  Very frustrating.

How I lost 67 Pounds

Between April 2012 and October 2013, I lost 67 pounds. People keep asking me how.
The short answer: diet and exercise.
The long answer: I had a plan. It started simple and grew more complicated. That plan is below.
DISCLAIMER: I am not a professional nutritionist or a professional physical therapist. This is not intended as advice, but to document what I did to answer others' questions. What worked for me might not work for you.
Disclaimers aside, let's make way for:

Morty's Weight Loss Plan

General weight loss

1. The big rule: don't try to do everything at once. Start small and build.
2. Don't lose weight too fast. For the first week or two, it's OK to lose a lot of weight, but after that, it should be 1-2 pounds per week. If you're losing weight faster than that, back off. Do less exercise and maybe relax the diet a bit.
3. You're not just doing this until you lose weight. If you go back to your old bad habits, you're just going to put the weight back on. The goal here is to make lifestyle changes that will let you lose the weight and then keep it off. And you need to exercise even if your weight isn't a problem. So your mindset should be "what can I live with for the rest of my life", not "what can I live with until I drop the weight."
4. NB: you do get to back off a little bit when you reach your goal weight. It's easier to maintain weight than to lose weight. Homeostatic equilibrium, baby.

Eating

1. Eat at least three meals per day
2. Eat at least 5 items of fruit per day. Usually a banana, two apples (fuji and something else), a pear (bartlett, d'anjou, forelle, or other green pear or red pear, but not packham) and a citrus (minneola tangelo, valencia orange, or other)
3. Eat at least one serving of vegetable per day. [Mom would be so proud.]
4. Eat at least one serving of fish per day. Canned fish works well. Examples: tuna salad (suitable for work), sardines in lemon sauce, sardines in mustard, smoked trout.
5. Watch out: don't bring "stinky" fish to work. Some people didn't grow up eating this stuff. Poor them.
6. Avoid starch. That includes bread, potato, pasta, or rice. A little won't hurt, but don't overdo it.  (I eventually added a daily whole wheat bagel.)
7. Eat at most one "meat" meal per day. The other meals should be just fruit and/or vegetables and/or fish
8. Meal idea: stir fry. Use 2 pounds of veggies for every pound of meat.
9. Meal idea: grilled steak and grilled veggies
10. Meal idea: Maiwand Kebab (21044, by the Safeway, not one of the other ones). Lamb kebab, substitute eggplant and chickpeas.
11. Eat fruit and veggies *before* "fun" food
12. If you're hungry, eat. If you're thirsty, drink. If you're tired, sleep.
13. While eating, pay attention to your hunger. If you're not hungry any more, stop eating. Eat slowly, so your body has time to adjust.
14. It's OK not to finish everything on your plate.
15. You can eat food that's healthy. You can eat (some) food that's tasty, even if it's not healthy. If the food isn't healthy and isn't tasty, don't eat it! This is especially a problem at restaurants, which tend to bundle "bad" foods with "good" foods. I don't much like french fries, and they are not healthy, so why do I eat them when they are served in restaurants as a side?
16. Tricks for dealing with restaurants: "hold" and substitutions. I tend to eat whatever is served to me, even if I don't like it -- I don't want to waste food. So, get them to "hold" it, so it won't be wasted. Or substitute for something healthier. Most restaurants are happy to substitute salad for french fries.
17. When eating out, partition your food. Don't eat more than you think you should. Remember, it's OK not to eat everything. The starving kids of the world won't be any more fed if you overeat.
18. When you want to drink juice or other sugar waters, drink just a small amount. The best part is the first swallow. Then slake your thirst with water.
19. The above works with most tasty+unhealthy food. Ice cream? Have a spoonful, and then eat something else.
20. You are allowed to make occasional exceptions. The bread at Maiwand 21044, for example. Just don't do it too often.

Exercise

1. "No pain, no pain." If it hurts, stop the exercise or decrease the weight.
2. Watch TV on an exercise machine (treadmill, exercise bike.) No TV watching from the sofa unless you are also keeping up with your exercise.
3. Never run two days in a row -- intersperse with bike work.
4. When you have time, spend extra time walking/biking at low intensity. This helps you lose weight. Keep it slow.
5. Split the weights into muscle groups. Do different groups on different days.
6. Gradually increase the load over time. I increase one setting per visit, gradually rotating through all settings. Since I use 12 different weight machines, that means I stay at a given setting for about 2 weeks before I increase it.
7. Don't increase by more than 5 pounds at a time. For machines that only go up by 10 pound increments, use 5-pound add-on weights.
8. If you are scheduled to increase the load but are having a lot of trouble with it, DO NOT increase the load. See "no pain, no pain" above.
9. Even if you are scheduled to stay at the same weight you have done before, if you are having trouble with it, decrease the weight. See "no pain, no pain" above.
10. Exercise every day if possible while trying to lose weight.
11. Missing one day occasionally is OK. Do not miss two days in a row. [When you're done losing weight, you might be able to back off to exercising every two days as a matter of course.]
12. High-speed exercise is good for the heart. Low speed exercise is good for weight loss. The border is at a pulse rate of about 180 - $your_age. Above that threshold, you don't burn fat. Do both kinds of exercise.
13. Per the above, you need a heart rate monitor. Be sure to get one with a replacable battery.
14. Normal exercise sequence: half an hour of swimming followed by half an hour of running/walking or biking followed by weight work.
15. Exerise every day. If you can't do every day, do every 1.5 days.
16. I try to exercise 7 times in a week. Sample schedule: Monday morning: run, group 1 (abs and arms). Tuesday morning: bike, group 2 (chest, thighs, legs, shoulders). Wednesday: repeat Monday.
17. Note that the above was not an all-at-once deal. When I started out, I was just going the running. After more than 5 months, I started the group 1 and group 2 exercised. A few months after that, I started the exercise bike. I phased in swimming about 15 months after I started, then dropped it a few months later.

Commands: noun, then verb

One of the little things that irk me: commands that start with a verb followed by a noun.

I fully understand why English-speaking people tend to put the verb first. In English, an imperative order is given verb first. "Insert this module! Delete this directory! Add this apt repository!" So English speaking programmers tend to use the same convention for program names.

Unfortunately, verb-first order breaks command searching via command completion. Suppose I want a module related command, but I can't remember the name. The part I'm most likely to remember is "mod". If it were "modins", "moddep", "modrm", etc., I could start typing "mod" and press <tab> and the various module-related commands would be listed. But if it's "insmod", "depmod", "rmmod", etc., I had better remember the particular verb used as well as the noun.

A related problem is that verbs tend to not be consistent. Why do we "ins" and "rm" modules but "add" and "del" users? The noun part is much more likely to be consistent. Once more, command completion comes to our rescue.

When I did Solaris admin, I was impressed that all their module commands started with "mod". I'm happy to note that people in the Linux world now mostly seem to get this as well. The early Linux module commands were "verb-noun" ordering, but the newer module commands are "noun-verb" -- "modprobe", "modinfo". Similarly, the early "user" commands were "adduser" and "deluser", but the modern equivalents are "useradd" and "userdel". Yay for progress!

[And now I have a reference for when I need to argue with someone on why they should rename their program! Yay me.]

Android configuration

I document all my normal Android settings, for when I have to configure a new device. Let's share.

1. settings
   1. security
      1. unknown sources: allow
      2. screen lock: pin
      3. automatically lock: 5 minutes after sleep
      4. power button instantly locks: off
      5. owner info: enter name and email
      6. verify apps: enable
   2. backup and restore
      1. automatic backup: enable
      2. automatic restore: enable
2. accounts:
   1. google
   2. dropbox
   3. facebook
   4. Mantano (now expired)
   5. netflix
   6. outlook web email
   7. skype
   8. tivo
   9. twitter
3. ADW (ADVANCED)
   1. actionbar: don't show
   2. dock: rotate with device orientation
   3. desktop position: ICS slider
   4. app drawer: ICS paginated
   5. transitions: normal scroll
   6. ADW Settings
      1. screen
         1. desktop columns: 5
         2. desktop rows: 7
      2. system
         1. advanced settings
            1. home orientation: portrait
   7. desktop setup
      1. icon row:
         1. phone
         2. beyond podcast
         3. chrome
         4. reader
      2. row: 1 (from bottom)
         1. power toggles icon (see below for details)
         2. widget beyond podcast 1x1 icon
      3. row: 2 (from bottom)
         1. widget connectbot frakir.org
         2. maps
         3. winamp
         4. folder
            1. facebook
            2. twitter
            3. flipboard
            4. google+
         5. play store
      4. row: 3 (from bottom)
         1. folder
            1. mantano reader lite
            2. AEPreader
            3. aldiko premium
            4. eReader Prestigio
            5. ZXReader
            6. HaTaNa"Ch
         2. OurGroceries
         3. folder
            1. Angry Birds
            2. Angry Birds seasons
            3. Bard's Tale
            4. Defender II
            5. Minecraft PE demo
            6. Sudoku
         4. folder
            1. MX player
            2. Music
            3. Mythfrontend
            4. netflix
            5. pandora
            6. tivo
         5. folder
            1. Gmail
            2. Messaging
            3. Outlook Web Mobile
            4. People
            5. Skype
            6. Talk
            7. YAIIC
      5. row: 4 (from bottom)
         1. folder
            1. Clock
            2. StopWatch and Timer
         2. Navigation
         3. folder
            1. Camera
            2. Camera MX
            3. DOF Calculator
            4. OneShot Cam
            5. Smart Voice Recorder
         4. folder
            1. settings
            2. ADW Config
            3. Authenticator
            4. battery indicator
            5. BlueAnt
            6. Downloads
            7. Dropbox
            8. ES File Explorer
            9. Gallery
            10. Power Toggles
            11. ROM Manager
            12. SGS3 Easy UMS
            13. StickMount
            14. SuperSU
            15. Task Manager
            16. Torch
            17. Traceroute
            18. UltraTools Mobile
            19. Wi-fi Web Login
         5. folder
            1. Tricorder
            2. AK47
            3. Android Lightsaber
            4. Android Lightsaber (#2)
            5. BlueScreen
            6. Earth
            7. Google Sky Map
            8. Periodic Table
            9. screen Crack
            10. Sonic Screwdriver
            11. Sonic Screwdriver (#2)
      6. row: 5 (from bottom)
         1. blank
         2. blank
         3. folder
            1. Barcode scanner
            2. BMI Calculator
            3. Chicon7
            4. DC Metro Map
            5. DC Metro Transit
            6. Goggles
            7. How to Tie a Tie
            8. Karl's Mortgage
            9. Local
            10. MyBMI
            11. NASA
            12. News and Weather
            13. RunKeeper
            14. Running
            15. Speed Dial
            16. The Weather Channel
            17. Translate
         4. RealCalc
         5. folder
            1. Titanium Backup
            2. APN Backup & Restore
            3. Call Log Backup & Restore
            4. SMS Backup & Restore
      7. row: 6 (from bottom)
         1. blank x5
      8. row: 7 (from bottom)
         1. blank
         2. Calendar
         3. Hebrew Calendar Widget (see below)
4. aldiko premium
   1. settings | display | page turn animation = off
5. automateit
   1. settings
      1. show popup messages: off
      2. show service notifications: off
   2. add rules
      1. application trigger
         1. application: map
         2. actions: composite
            1. GPS: on (phone only)
            2. mobile data: on (phone only)
      2. power connected
         1. actions: composite
            1. GPS: on (phone only)
            2. bluetooth: on
            3. wifi: on
      3. power disconnected trigger
         1. actions: composite
            1. GPS: off (phone only)
            2. bluetooth: off
            3. wifi: off
      4. application activated trigger
         1. application: MX Player Pro
         2. action: set screen brightness 100%
      5. application deactivated trigger
         1. application: MX Player Pro
         2. action: set screen brightness automatic
6. AVG
   1. activate
7. battery indicator
   1. just start it
8. call logs backup and restore
   1. preferences
      1. backup folder: external card
      2. schedule backups
         1. enable
         2. 4am
         3. repeat 1 day
9. connectbot
   1. set up hacker's keyboard first
   2. connect ssh to morty@frakir.org
   3. connect ssh to work
   4. connect local
   5. create shortcut widgets for morty@frakir.org
10. dropbox
    1. configure account
    2. upload phones
       1. upload existing photos: no
       2. skip
11. email
    1. settings
       1. application
          1. auto-advance: message list
12. ES File Viewer
    1. settings
       1. file settings
          1. show hidden files: yes
       2. view settings
          1. view: details
13. facebook
    1. log in
    2. sync (contacts): Sync all (note: won't be present on tablet)
    3. settings
       1. sync photos: off
       2. messenger location: off
       3. sync contacts: sync all (note: won't be present on tablet)
14. hacker's keyboard
    1. configure input methods (also under settings | keyboard)
       1. hacker's keyboard
          1. enable
          2. settings
             1. keyboard mode, portrait: full 5-row layout
    2. set current input method (also under settings | keyboard)
       1. hacker's keyboard
15. Hebrew Calendar 3x1 widget
    1. hebrew date changes at: midnight
    2. location for candle lighting: enter location manually: 21044
    3. Language: Hebrew
    4. minutes before sunset to light candles: 18
16. mantano
    1. settings
       1. bookshelf
          1. import folders
             1. add: /mnt/inbooks
             2. del: /mnt or other defaults
17. ourgroceries
    1. send auth request to main acount
18. MX player
    1. settings
       1. decoder
          1. S/W decoder (local): yes
19. netflix
    1. log in
20. power toggles
    1. create a widget
       1. toggles:
          1. hotspot (wifi)
          2. wifi
          3. bluetooth
          4. gps
          5. mobile data
          6. screen lock
          7. volume toggle
          8. brightness quad
       2. transparency: about 50%
    2. under the app:
       1. notification widget
          1. enable
          2. conigure
             1. two rows
             2. row1: as per widget above
             3. row2:
                1. flash light
                2. screen light
                3. data sync
                4. sync now
                5. airplane mode
                6. play/pause music
                7. rotation lock
21. realcalc
    1. settings
       1. RPN mode: yes
       2. Enable Radix modes: yes
       3. swap percent and 1/x: yes
22. tricorder
    1. obtain from your dropbox account
    2. settings
       1. sound level: quiet sound
23. SuperSU
    1. settings
       1. show notifications: no
       2. clear logs after: never
24. wifi web login
    1. log in at work
    2. log in at gym
25. root phone (ADVANCED)
    1. download heimdall, recovery.img, and CWM file CWM-SuperSU-v0.87.zip to linux system
    2. build heimdall
    3. copy CWM file to phone external card
    4. reboot (#1) phone, while holding down buttons: volume-down, power, and home
    5. at prompt, press volume-up
    6. you should now be in "ODIN mode" (small print) and "Downloading..."
    7. on your PC, sudo ./heimdall flash --recovery recovery.img
    8. watch phone closely! If you miss your window, you will need to reflash until it works
    9. When it reboots (#2), hold down buttons: volume-up, power, and home
    10. If you boot into the normal phone OS, you missed recovery mode. Go back to the reboot #1 and reflash.
    11. You should boot into CWM based Recovery. If you boot into Android recover, go back to reboot #1.
    12. If you got into recovery mode, congrats!
    13. In the recovery menu, use volume-up, volume-down, and power to select
    14. select "install zip from sdcard"
    15. select "choose zip from sdcard"
    16. select "firmware"
    17. select CWM file
    18. select "yes"
    19. select "go back"
    20. select "reboot"
26. Upgrading to a different firmware (ADVANCED)
    1. backup phone apps using Titanium backup
    2. backup call logs to external SDcard
    3. backup SMSs to external SDcard
    4. backup APNs; copy from local SDcard to external SDcard
    5. backup ADW launcher settings; copy from local SDcard to external SDcard
    6. download and transfer to phone sdcard:
       1. desired image
       2. google apps ("gapps") for desired image
    7. do usual root steps, up to second boot
    8. using clockwork recovery:
       1. make a backup of the system firmware
       2. wipe previous data
       3. install image
       4. install google apps ("gapps")
       5. reboot
    9. once booted
       1. configure wireless
       2. configure google account
       3. go to google play
          1. stop downloads (if they are happening)
          2. install titanium backup
       4. go to titanium backup
          1. menu | batch actions
             1. restore missing apps with data
             2. DO NOT: restore missing apps and all system data
             3. DO NOT: restore all apps with data
       5. reboot

Android Apps

[Last Updated: 2013-05-06]

Every now and again, geek chats turn to favorite Android apps. I've been meaning to make a list of mine. Here is that list, starting with the really useful, non-obvious choices first. If you have a great one that I left out, please let me know!

[Note: a few are labelled as requiring root. For these few, if you are not very technical, you may not want to try to use them.]

Apps that everyone can use

1. MX Player -- video player that is much more flexible than the built-in player. Versions: free (full, ad-supported); pro.
2. RealCalc -- scientific calculator. Has support for Radix modes, RPN, and other nifty features. Versions: free (almost all features); pro.
3. OurGroceries -- shared list manager. Has clients for Android, iOS, and generic web. Free, ad-supported.
4. PowerToggles -- replacement (up to 8 toggles) for the default power control widget. Free. Note: some functionality requires root, but on Samsung, is worth installing even without root.
5. ADW Launcher -- replacement for the main interface that comes with your Android device. Will let you increase the number of columns and rows. Very useful if you have a device that limits you in this department. Free.
6. BeyondPodcast -- nice podcast manager. Much nicer than Google's "Listen" app. Versions: trial (limited); pro.
7. ES File Explorer File Manager -- browse files directly. Free.
8. Call log Backup, APN backup, SMS Backup -- free backup apps.
9. Mantano Reader -- ereader app, my current preference.
10. WiFi Web Login -- automate login to wifi hotspots. Very useful if your work and/or gym wifi requires a login.

    More specialized apps

11. Connectbot -- ssh client. Free.
12. Hacker's keyboard -- replacement Android virtual keyboard. Includes, control, alt, escape, and other useful keys. Free.
13. Stickmount -- replacement for USB mass storage support for devices that don't come with. Free. Note: REQUIRES ROOT.
14. Speed Dial -- replacement speed dial call list for phones that have a crappy phone app. Free.
15. Battery Indicator (Darshan) -- nice battery widget.
16. AutomateIt -- automatically change settings and do other actions based on triggers. Versions: free (limited); pro.
17. BusyBox -- linux tools. Free. Note: REQUIRES ROOT.
18. DOF Calculator (Aimen) -- for photographers to calculate depth-of-field. Has advanced mode that will let you fill in numbers -- handy for, say, shuttle photography. Free.
19. Titanium backup -- lets you backup all your apps and setting, e.g. before an upgrade. NOTE: REQUIRES ROOT. Versions: free (limited); pro.
20. Google Authenticator -- lets you build two-factor auth systems.
21. Google Goggles -- work with barcodes.
22. Hebrew Bible -- for looking things up on the fly.
23. Hebrew Calendar Widget
24. Karl's Mortgage Calculator -- calculate mortgage under various conditions. Free.
25. How to Tie a Tie -- diagrams that include the more obscure tie types
26. NASA App -- keep track of NASA
27. mythfrontend -- watch TV from your MythTV player
28. Periodic Table -- yay for chemistry!
29. Presto Sound Library -- a "beta" but it costs money. Will let you play your podcasts in BeyondPodcast at faster than 1x.
30. Skymap (google) -- nifty astronomy resource
31. Stop Watch & Timer
32. SuperSU -- manages root access. Note: requires root.
33. Task Manager (Rhythm Software)
34. Tivo -- control your tivo. Cannot yet stream content from a tivo. Free.
35. The Weather Channel -- widgets to track weather
36. traceroute (srcguardian)
37. UltraTools Mobile -- traceroute and other tools to troubleshoot networks
38. Yaaic -- IRC chat program. Free.
39. Go Clock Widget
40. Antivirus AVG. Free. Not sure if it's worth it. ;)
41. Call Your Folks -- reminder to call parents.
42. Nike+ Running
43. Runkeeper
44. MyBMI
45. BMI Calculator

    Some app equivalents of popular websites and desktop apps. Also apps that tend to come with your devices

46. Google Reader -- keep up with your RSS feeds. Unfortunately, limited to 30-day retention. Still one of my most heavily-used apps.
47. Gmail -- keep up with your google mail
48. Google Calendar
49. Google Earth
50. Google Play
51. Google Play Books
52. Google Play Movies and TV
53. Google Play Music
54. Google Search
55. Google Translate
56. Dropbox
57. facebook
58. firefox
59. Flipboard
60. IMDB -- search IMDB. Sometimes less useful than the website.
61. Maps
62. netflix
63. Skype
64. Street View on Google Maps
65. twitter
66. Voice Search (google)
67. WinAmp -- yes, it's available for Android.
68. Youtube

    Toys and games (all free except as indicated)

69. AK-47 -- toy gun.
70. Android Lightsaber
71. Angry Birds
72. Angry Birds Seasons
73. Bard's Tale
74. Binary Time Widget
75. BSOD
76. Defender II -- free to play. After a certain point, upgrades cost money. :(
77. Radiant Defense -- free to play castle defence. After a certain point, upgrades cost money.
78. ScreenCrack
79. Sonic Screwdriver Gadgets
80. Star Wars Light Saber
81. Sudoku (Frank and Chase)
82. Tricorder (not available from the app store)
83. X-sonic Screwdrivers

    Some apps I no longer use/need

84. Power Control Plus -- can have a whole lot of toggles, but can't set GPS even with root and running as a system app.
85. Adobe Reader -- I no longer run Adobe software by choice
86. Advanced Task Killer (rechild) -- don't like current permissions
87. Aldiko -- eReader app. Has problems rendering the covers of some of my books. I've switched to Moon+ Reader.
88. Android Tethering -- prefer wifi tethering
89. BarcodeBank -- use google goggles instead
90. Battery Widget (GeekyYouUp) -- prefer Darshan
91. Brightest Flashlight -- prefer the flashlight that is part of Power Toggles
92. Color Flashlight HD -- prefer the flashlight that is part of Power Toggles
93. Power Control Widget -- a power control widget that can have an arbitrarily large number of controls/toggles. Unfortunately, it doesn't work on my rooted ICS Samsung S3.
94. Moon+ Reader -- ereader app. Doesn't paginate correctly.
95. Nook -- implements DRM. No thanks.
96. Out of Milk -- shopping app. No easy sharing.
97. eReader Prestigio -- ereader app. Put an ad in my notification area.
98. Racing Live -- free to play.
99. Shop Savvy Barcode scanner

Tips and tricks

You can use widgets to make shortcuts. This is really useful for navigation -- I have shortcuts for home, work, gym, parents, and some others. Also for google reader -- I have a shortcut for slashdot.

With AutomateIt, you can have the GPS and 4G automatically turn on when you turn on navigation. This may be updated in the future. :)

Why hasn't IPv6 been deployed yet?

A lot of articles talk about why IPv6 is needed, and some talk about why IPv6 is great even if it's not needed. Many people are concerned that IPv6 has not yet been deployed. But one question I've discussed several times recently but have never read in print: why hasn't IPv6 been deployed? There are a lot of reasons.

Compatibility

When IPv6 was designed, it wasn't perfectly compatible with IPv4. That is, when one switches to a "pure" IPv6 model, the existing Internet becomes inaccessible.

Most other software upgrades try hard to retain compatibility. For example, when one language of the web, HTTP, was upgraded from 1.0 to 1.1, a lot of care was taken to ensure backwards compatibility. Any web browser or web server that talked the newer version could also talk the older version. This made the upgrade seemless. Only after upgraded clients became uniquitous did server administrators start taking advantage of the features of the new version. An upgraded device is certainly no worse off than without the upgrade. Even today, ancient web servers written in the old way can continue to provide web content without modification.

IPv6 doesn't automatically maintain compatibility. If one "simply" upgrades from IPv4 to IPv6 without additional effort, one loses access to the current IPv4 Internet. The IPv6 answers to this problem are "dual-stack" or "IPv4 gateways". In the first case, the prospective IPv6 user must maintain an IPv4 infrastructure in parallel to the new IPv6. In the second case, the prospective IPv6 network administrator must maintain a translation device between the IPv6 and the IPv4 world. While this works, it requires additional effort.

Effort

IPv6 requires a lot of additional effort. The home computer user or corporate user won't have much to do, but the various network infrastructure people have to learn new protocols, replace or upgrade equipment that doesn't support IPv6, and replace or upgrade applications that don't support IPv6. This is not an effort that is worthwhile without a mandate or other strong incentive.

No central authority mandating IPv6

Other major software upgrades have happened because an authority forced the issue. For example, one of my older coworkers told me that the upgrade to Ipv4 was mandated to occur on a certain day. After that day, the old version would no longer be supported. The US government controlled the Internet at the time, and it was primarily used for research, so such pronouncements were possible. No one has the authority to do that today.

Incentive

When new Internet addresses run out, existing devices on the Internet will not immediately be inconvenienced. On that looming date, it will gradually become more difficult to add more devices, although partial workarounds (such as HTTP/1.1 and NAT) are now well-established. But the Internet will not immediately "break". It will be business as usual for most existing devices.

Meanwhile, there are no significant resources that are IPv6-only today. Until there is a significant resource that is IPv6-only, or IPv4 is in danger of "breaking", IPv4 is good enough for most people.

But until most people have IPv6 a site would be crazy to make itself IPv6 only.

This is a classic chicken-and-egg problem. No one wants to upgrade because no one has upgraded.

The classic way the software world fixes this kind of problem is by sneaking in the upgrade using an easy, backwards compatible upgrade. Except, as above, the IPv6 upgrade is neither easy nor backwards compatible.

Another way to fix this is for one or more large entities to sacrifice and take the first step. The US government is trying to do this. But it's too little, too late.

Hardware support

Even in 2011, there are plenty of new devices being sold that do not support IPv6. These include network routers, switches, firewalls, and more esoteric devices such as sensors, digital matrix switches, fileserver appliances, and others. Each IPv4-only device sold is making the problem a little worse. How can we upgrade if we have to throw away all these investments?

Application support

For an IPv6 upgrade to be compelling, one doesn't just need support at end user stations and the routers, switches, and other network gear. One also needs support in applications.

That means that if I run some kind of application, either as an end user or as a server administrator, I need all my applications to work correctly after the IPv6 upgrade.

Unfortunately, many applications are not IPv6-ready, themselves. So even if I am prepared to go to the effort to upgrade, how can I do so if all the software I use won't work? The software authors don't feel the incentive to upgrade any more than anyone else does.

Conclusion

We are in trouble. Some of these problems might have been solvable 10 years ago, had they been recognized. At this point, it's too late. The Internet will almost certainly go through a protracted period of having IPv4 addresses depleted but IPv6 not yet widely deployed.

Issues with TCL and Expect

Issues with TCL:

* scope is insane. There is no automatic inheritance of variables
from the global scope. If you want a variable from the parent
scope, you need to declare this by using the "global" keyword.
There are various other kinds of scope you can do, including going
into the caller's scope.

* the language is barely tokenized at all. If there is a basic syntax
bug, the interpreter is likely to not pick up on it until that
particular code path is run.

* There are no forward declarations of functions. If you want to use
a function, you have to define it before you use it.

Issues with expect:

* the documentation encourages people to do "send "$whatever\r";
expect $prompt". In a lot of cases, though, sending $whatever will
result in a prompt regardless of whether it also resulted in an
error or not. This encourages sloppy code. Better guidance might
be "send "$whatever\r"; expect "$whatever\r\n$prompt", because that
checks that the host returned a prompt immediately after echoing
$whatever.

* Bad things can happen under three special error conditions: eof,
timeout, and full_buffer. It would be nice if there were a default
handler for these that threw an exception, to force programmers to
be aware of them. The handler could be an expect_after_after, so if
the programmer tests for them in expect_before, expect, or
expect_after, that test overrides. It might be triggered by a
special syntax (i.e. expect_sanity or something) so as to avoid
problems with backwards compatibility.