Networking: View PMTUD cache on linux

ip route show cache

ip route show cache <ip>

Wireshark shows packets larger than MTU

TCP segment of a reassembled PDU

wireshark shows a frame with 2574 Bytes,
tcpdump shows the same frame as 2574 Bytes

A very good post:
http://sandilands.info/sgordon/segmentation-offloading-with-wireshark-and-ethtool

and you are sure that the MTU is 1500 or lower (no jumbo frames), since you saw the MSS in the SYN and SYN/ACK, so both sides are certainly below 1500.

Apparently this is because of the NIC doing tcp segmentation offloading:


 # ethtool -k eth0
Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: on
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: off
large-receive-offload: on

ethtool -K eth0 tso off
ethtool -K eth0 gso off

I turned off tcp first but the generic did prevail so I turned off gso and thought I saw only smaller packages but when enabling and disabling it again I did not see the small packets anymore, so maybe a restart is necessary.

Would be nice to see it working or not the 2nd time you disable it. But I won't restart the system.

Networking: MTU

http://www.elifulkerson.com/projects/mturoute.php

Networking: MTU MSS PMTUD

http://packetlife.net/blog/2008/aug/18/path-mtu-discovery/

http://www.nil.si/ipcorner/IP_Fragmentation

http://www.cisco.com/en/US/tech/tk827/tk369/technologies_white_paper09186a00800d6979.shtml

Networking: Troubleshooting: MTU with ping -l 1472 -f

windows:
ping -f -l 1472 destIP


linux:
ping -M do -s 1472 -c 1 destIP

linux: fat32 bootable usb stick with ESXi

http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.install.doc_50%2FGUID-33C3E7D5-20D0-4F84-B2E3-5CD33D32EAA8.html

linux: ubuntu: map c drive from a windows machine over the network

Start Nautilus, i.e. click on the home folder icon.

Press CTRL-L (for location) and enter smb://<ip or name>/share, e.g. smb://10.0.0.1/c$

It will then ask for domain, username and password

linux: ubuntu: change keyboard mapping from terminal

setxkbmap fr


http://wiki.laptop.org/go/Keyboard_Files

linux: multiple default gateways (even for aliases)

A really great blog entry, which solved all my issues in no time. The only thing is now that I have multiple distributions and have to find out where to place the commands so that after a reboot it will come back correctly.

http://kindlund.wordpress.com/2007/11/19/configuring-multiple-default-routes-in-linux/

linux: alias

ifconfig eth0:0 10.0.0.2 netmask 255.255.255.0 up

ifconfig eth0:0 10.0.0.2 netmask 255.255.255.0 down

iPad Pens: AluPen and/or Bamboo Stylus

Finally this week has my bamboo stylus arrived from Hong Kong, as it was cheaper to buy than local.

Cost $31 including shipping.

I have been using AluPen for almost a year and was carefully avoiding buying any other pens since I was extremely disappointed by almost all except AluPen.

Now I read a lot of rave reviews about bamboo stylus and decided to buy and after a few hours I can clearly say it is a good pen.

BUY.

(Make sure you had the chance to test the Pen because choosing between AluPen and Bamboo is not always easy. I like to use Faber Castell 0.7 thick thick wooden pencils and then I switch back to my wooden 0.5 Lamy pencil and then there is also the new 0.5 Faber Castell triangle rubber pencil which comes in handy.)

Will this mean I will be happy, no! The problem lies between the keyboard (or Pen) and the iPad; which means me. I just can not cope to really work efficiently with the iPad no matter how hard I try. Using about 10 note taking applications and going through iterations of versions but still fail. Most of them are used differently and don't give full flexibility, are slow, buggy etc.

The biggest issues are:

• With the pens you cannot write as small as on paper and if you try like I do then you'll probably end up missing always the initial stroke. All applications that automatically zoom or have a real manual gesture zoom are good but hard to work with.
• Some strokes get lost, especially the first ones of a Character etc.

I cannot use the iPad for note taking. I should stop trying.

 I failed to use Windows XP Tablet PC on Motion Computing around 2004, because XP Tablet and Windows 7 tablet is not really made for use with a Pen. They never made the applications behave the same and your arm had to cover distances that were by far more than inconvenient and inefficient. Compare what you can achieve with a perfect mouse like Logitech MX 1000 or the newer models.

Nothing beats a letter/a4 notepad with a Lamy or Faber Castell pencil.

Maybe the KNO Tablet or something else, an letter/A4 iPad anyone?

Interesting read: Why the iPad has to be made in China

http://motherboard.vice.com/2012/4/19/why-the-ipad-has-to-be-made-in-china--2

Interesting Read: Apple vs. SeattleRex

http://www.seattlerex.com/seattle-rex-vs-apple-the-verdict-is-in/

The quest for the ultimate keyboard for iPad is over: Logitech Ultrathin Keyboard Cover

I would have loved something like the apple wireless keyboard to appear on the market attached to the iPad like a smart cover.

My wishes have almost come True.

Logitech Ultrathin Keyboard Cover to the rescue:

http://www.logitech.com/de-ch/tablet-accessories/keyboards/devices/ultrathin-keyboard-cover?WT.ac=ps|9859|hp

If the keyboard is a bit better than the old zagg/logitech product it's a 100% BUY!

It's probably not as comfortable as the wireless keyboard from Apple but it might fit.

http://www.theverge.com/2012/4/18/2958455/logitech-ultrathin-keyboard-cover-ipad-impressions
http://www.zdnet.com/blog/mobile-news/logitech-ultrathin-keyboard-cover-for-the-ipad-smart-cover-meets-keyboard/7511

Interesting read: Early History of Jack Tramiel

http://www.commodore.ca/history/people/jack_tramiel_early_history.htm

Excel: All m acros for use in all excel files

• show developer ribbon
• Record Macro enter some dummy text as name and select personal workbook
• Stop Recording (you did nothing in between, right?)
• Press Visual Basic or ALT-F11
• Select Personal Workbook and Module1, click view code
• replace everything with a sub end sub, e.g. the highlight from a previous post

http://office.microsoft.com/en-us/excel-help/create-and-save-all-your-macros-in-a-single-workbook-HA102174076.aspx

Excel: filter rows based on cells that contain non-ascii characters

After running the script to highlight non-ascii characters you can use the autofilter of excel 2010 and filter on color!

http://support.microsoft.com/kb/213923

Excel: Highlight non-ASCII characters in Excel

http://www.excelforum.com/excel-new-users/821220-need-help-finding-all-non-ascii-characters-in-spreadsheet.html

Kudos to  protonLeah, many thanks. As well as for MAP-Daniel.

This is what I used:

Sub NonAscii()
    Dim UsedCells   As Range, _
        TestCell    As Range, _
        Position    As Long, _
        StrLen      As Long, _
        CharCode    As Long
   
    Set UsedCells = ActiveSheet.Range("A1").CurrentRegion
    For Each TestCell In UsedCells
        StrLen = Len(TestCell.Value)
        For Position = 1 To StrLen
            CharCode = Asc(Mid(TestCell, Position, 1))
            ' If CharCode < 32 Or (CharCode > 32 And CharCode < 48) Or (CharCode > 57 And CharCode < 65) Or (CharCode > 90 And CharCode < 97) Or CharCode > 122 Then
            If CharCode > 127 Then
                TestCell.Interior.ColorIndex = 36
                Exit For
            End If
        Next Position
    Next TestCell
End Sub

Ascii: Ascii table

http://www.asciitable.com/

Excel: Add a VBA as a macro

http://msdn.microsoft.com/en-us/library/ee814737.aspx

Interesting Read: Security: Author of Zeus jailed

http://www.dailymail.co.uk/news/article-2124114/Computer-hacker-Edward-Pearson-Lendale-York-stole-million-people-s-personal-details-jailed-half-years.html

Interesting Read: Wired: Google, Amazon, and Microsoft Swarm China for Network Gear

http://www.wired.com/wiredenterprise/2012/03/google-microsoft-network-gear/

Interesting read: Article on Wired about linked.in founder

http://www.wired.com/epicenter/2012/03/ff_hoffman/

OS X: Snow leopard - assign application to a specific desktop

I find myself working more and more with fullscreen applications on OS X and use the 4 finger gesture to switch between them. Some applications don't let themselves use in this mode and used to overlay all other applications.

Then you start again thinking, wouldn't it be nice to always have that application on it's on desktop, where you can just switch over?

Using missing control move the application to the desktop (drag and drop) of choice and then select the application from the dock and right click->Options->Assign to This Desktop and you're done.

Word 2010: Word Annoyances #1, paste that picture now!

Why sometimes easy things get extremely complicated and no real solution has been provided for 2 years. As an old fried would have said: Just past that picture you ....... How to copy/paste an image into word and have it automatically resized to the correct cell width? http://social.technet.microsoft.com/Forums/nl/word/thread/82023079-f911-4e23-9ac5-f2e0ae120826

OpenGL: what version (on windows)?

Sometimes strange things pop up and you have no clue as how to get fast to a good answer.

What is the current version of OpenGL your machine has installed?

No answer yet.

Update:

There is a nice blog entry about OpenGL Extension viewer:

http://blogs.esri.com/esri/supportcenter/2012/03/15/what-version-of-opengl-do-i-have-and-do-i-have-the-latest-drivers-for-my-system/

2 tools, which tell you what version you have

•  GPU Caps viewer    http://www.ozone3d.net/gpu_caps_viewer/
• OpenGL Extension Viewer http://www.realtech-vr.com/glview/

But some info from http://www.opengl.org/wiki/Getting_started

Without drivers, you will default to a software version of OpenGL 1.1 (on Win98, ME, and 2000), a Direct3D wrapper that supports OpenGL 1.1 (WinXP), or a Direct3D wrapper that supports OpenGL 1.1 (Windows Vista and Windows 7). None of these options are particularly fast, so installing drivers is always a good idea.

Which means if you have no drivers installed you end of with OpenGL 1.1 at least on Windows.

What tools could provide some answer? I mean from a standard Windows 7 installation (no additional software)?

System information 

On W7->Start->All programs->Accessories->System Tools->System Info

%windir%\system32\msinfo32.exe


Does not look like it.

Windows: Windows Event Collector, anyone?

Need to investigate Windows Event Collector, any good resources?

So far I have only 1 starting point:

http://msdn.microsoft.com/en-us/library/windows/desktop/bb427443%28v=vs.85%29.aspx

Webtools: HAR (HTTP online viewer) online viewer

http://www.softwareishard.com/har/viewer/

Internet Tech: Interesting read

http://httparchive.org/about.php
http://www.stevesouders.com/blog/2009/10/19/http-archive-specification-firebug-and-httpwatch/

Blogs: to follow

http://www.bart-timmermans.nl/
http://stevesouders.com/
http://www.softwareishard.com/blog/

PDF: online PDF creation from webpages

Have used multiple services from the iPad and desktop but have not made use of them lately. Why?

Because on OS X this is built in. They made one of the most usable PDF viewer/modifier (no real editor) but they also crippled it's functionality again.


http://blog.nitropdf.com/2008/01/free-online-web-services-to-create-view-share-and-edit-pdf-files/

Google Chrome annoyances #2: PDF print and blogger.com data loss

It has been some time that I have been relying on features from Chrome to make life easier, since in the past some of the functionality caused me big headaches.

I still use google chrome and my number one feature is the Omnibar. Everything else just sucks. But there is hope as safari has announced that from 5.2 there will be as well the Omnibar. Horray!

OK here we go:

PDF print

Clever function, I need it all the time since I want to keep many webpages in PDF form for storage etc. But I couldn't get chrome to create a PDF I can use since it just slices through text and graphics. Something IE2 has done 99 years ago for web page printing.

Blogger.com

Everytime I work on blogger.com from google chrome I loose data, the publish and update sometimes works sometimes it doesn't. If I add some line and then maybe another I press publish and nothing happens. If I leave the page data is lost. If from the same machine I use firefox 11 to do the same I never ever have any issue. So I stop using it for this purpose.

General webpage compatibility

I use many different computer vendor systems and their web management software and about 90% of all don't work. With firefox it is about a 10% chance that some old IE page won't work. And with IE it is like 95% of the webpages work but only about 30% are really usable due to speed problems. Most of the extjs pages have big issues.

Syslog: RFC 3195 resources

http://blog.gerhards.net/2009/01/rfc-3195-back-in-game.html

http://www.adiscon.com/en/

http://www.rsyslog.com/

http://www.liblogging.org/

http://tools.ietf.org/html/rfc3195

Windows: Event logs to syslog, alternative to snare?

You want to get windows event logs to another machine, maybe a central log server. Then usually you can use WMI (somewhat limited in eps and memory consumtion can be an issue) or you use some kind of agent. Snare is one of the available tools.

But I just came across another tool but I do not have heard about it and how it compares to snare. Do you?

http://code.google.com/p/eventlog-to-syslog/

Windows: Cool tool to solve uninstall issues on Windows Systems

Are you having an issue removing a software from your windows computer? Are you already frustrated enough and don't want to do some registry cleanup and fixing?

Why don't you give a Microsoft Fixit a try. They provide a tool that helps you install / uninstall software.

And as always send feedback about other solution you use.

Make sure you select the advanced download part and get a portable version, that you then can put on your MagicTool stick.

http://support.microsoft.com/mats/Program_Install_and_Uninstall

Firefox: How to enable automatic authentication/login using ntlm (Sharepoint and others?)

If you don't like to use IE due to whatever reasons and hate to have to login to your business webpages, where IE just works but firefox always nags you with a login prompt.

Get rid of it now, this is how:

• Open firefox, type in the address bar about:config
• acknowledge that you are aware of loosing your warranty
• type in the search pane uris
• Change the value of the two ...trusted-uris Preference Names found (see screenshot below) to a comma separated list of the domains or hosts you want, e.g. mydomain.com,myotherdomain.com

If you access a server with only the hostname, e.g. you put in the address bar mysharepoint, you will get prompted with a login box. To avoid this add the hostname also to the comma separated list.

example:   ad.domain,companyweb.com,mysharepoint

If you access mysharepoint now it will not ask for the login credentials and also not if you try to access mysharepoint.ad.domain.

Have fun.

Visio: How to protect shapes from being selected/moved inadvertently? Use layers!

Have you spent enough time in visio trying to select multiple objects using the mouse but ended up in some text entry for an underlying shape?

I have.

So from now on I use layers (not the background page) and will lock out the layer with my blocks of rectangles that are containers to place shapes in.

Here are some resources:

http://www.msoffice.us/Visio/(Visio%202010)%20Creating%20Stencils,%20Master%20Shapes,%20and%20Templates.PDF

http://office.microsoft.com/en-us/visio-help/about-locking-shapes-and-preventing-changes-to-files-HP085050461.aspx

Excel: Convert a column of input into a row separated by commas

So what was necessary to do this?

• have your columns with data
• select your columns and choose cut (CTRL-X)
• select an empty row or another worksheet and paste (CTRL-V), change mode to transpose
• copy the row to word
• select table->layout->convert to text
• replace SPACE by nothing
• select the text and copy and paste into the data validation source field

Some info I found but I did not want to use vba and the workaround with word had 2 issues.


http://superuser.com/questions/240858/convert-a-column-into-a-comma-separated-list

Some info about transpose:

http://office.microsoft.com/en-us/excel-help/rotate-data-by-converting-columns-to-rows-or-vice-versa-HP005203138.aspx

Excel: Data validation; how to achieve case sensitive?

I have been using data validation in excel for some worksheets where I use the columns as inputs for a formula at the end of the row.

But I was not aware that it is not case sensitive, i.e. all the entries in the second worksheet like WAN do not take effect. A user can type wan and then continue.

To achieve case sensitivity you have to actually put all possible entries into the dialog of the data-validation->source as a comma separated list.

Source    WAN,LAN,CAN,MAN...



A very good resource is also http://www.contextures.com/xldataval01.html

Will I buy the new iPad? continued...

After playing around in our local shop I have to say that I forget to put my old iPad2 next to it to have something to compare.

I use my iPad 2 about 2-4 hours a day, i.e. stretched over a 16 hours day. And for me the new iPad did not seem different than what I have:

the weight

• a non issue, had only 15 minutes to play around but it felt good

the feel and touch

• same as today, did not notice that it is thicker

the screen

• looks a little bit sharper, but I was not blown away. Which is sad because I expected from this single feature a miracle. It looks really great, but I did not feel the urge to buy immediately solely on this.

the camera

• feels great and fast but somehow the pictures are a bit wobbly and the video looked a bit grainy. Compared to the old iPad this is incredibly better, just look at the photo in the previous post. This for me is an argument to buy the new iPad but it is not strong enough.

the battery

• cannot comment, but the reports say that it will take much longer to load. Just this morning: yesterday I used the iPad at lenght and when I woke up the battery was at 3%. I plugged it in and 40 minutes later I had 42% battery load. I hope that the new one will not take double or more time to load.

If you don't own an iPad already, it will be a sure thing. If you have an iPad 2 you have to have really good arguments and enough cash to hand out. My iPad 2 is not yet a year old.

The new iPad should have come with water protection like the one from liquipel or hzo. And more importantly it should have complete glass and chassis protection. Today this is possible but only with an additional case (another post).

Original Post
http://engineeringmadness.blogspot.com/2012/03/will-i-buy-new-ipad.html

Accessory: Stump stand comes with a nice rubber band (;))

If you buy a stump stand it comes with an additional accessory at no cost; the rubber band.

From the beginning I liked the stand and think it is currently king, but also the rubber band has its benefits, e.g. as an additional layer of security on your wallet.

By the way this photo was taken the now old iPad 2. I hope these grainy kind of pictures will  not have cult following as some other do. Did I mention that the photo is really ugly?

iPad: What do Walt and David have to say?

As always I like to read the review of Walt and David, so here you go if you want to read it yourself:

http://allthingsd.com/20120314/new-ipad-a-million-more-pixels-than-hdtv/

http://www.nytimes.com/2012/03/15/technology/personaltech/the-new-ipad-is-much-the-same-only-better.html

Photo found by searching google images: walt mossberg david pogue

As it has been the last couple of years the hardware improvements have been very gradual and smooth. It looks like they are now capable of handling a large number of different devices.

I have had to download about 5 different IOS updates for the last iFamily update! But contrary to other years it was only a delta update and not the full IOS download!

I miss the times when we were introduced to brand new devices or big improvements, i.e. I'm still in love with the first unibody aluminum MacBook and have not seen a reason to upgrade to any other model. As well as the AppleTV, where I'm going to stay to the old black box and not invest into the new. iMac/iPhone is the same.

The only problem I have is the iPad. It does not yet fit my desired purpose, none of the others do by far, but I would like to get a decent camera and have a better reading experience. I will have to work with it and then decided but currently my buying decision is HOLD.

Bookmarks: Firefox 11 is out, includes add-on sync

Well apparently they also extended the sync feature like every other browser. So they now fully support a range of sync options. New addition is add-on sync. Maybe I have to try their bookmark sync and integrate it into the current solution described in a previous post.

Anyway. iCloud is the leading sync and then I need to inject these into chrome, firefox and IE

They also have a nice looking what's new section. See link.

http://www.mozilla.org/en-US/firefox/11.0/releasenotes/

snmp: Quickly check snmp access and get System description (using snmp V1)

You want to quickly check what a system responds with as system description use:

snmpget -v 1 -c public 1.1.1.1 .1.3.6.1.2.1.1.1.0

SNMPv2-MIB::sysDescr.0 = STRING: Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(19)EA1c, RELEASE SOFTWARE (fc2)
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Tue 03-Feb-04 09:38 by yenanh

Name	sysDescr!@#.iso.org.dod.internet.mgmt.mib-2.system.sysDescr
OID	.1.3.6.1.2.1.1.1
MIB	RFC1213-MIB
Syntax	DisplayString (SIZE (0..255))
Access	read-only
Status	mandatory
DefVal
Indexes
Descr	A textual description of the entity. This value should include the full name and version identification of the system's hardware type, software operating-system, and networking software. It is mandatory that this only contain printable ASCII characters.

snmp: snmpget: No securityName specified

snmpget: No securityName specified

we use snmp v1 and running the command without specifying -v 1 results in this error. I.e. the default is to use Version 3 which requires you to specify a username and password.

snmpget -c public 1.1.1.1 .1.3.6.1.2.1.1.1.0
snmpget: No securityName specified


snmpget -v 1 -c public 1.1.1.1 .1.3.6.1.2.1.1.1.0
SNMPv2-MIB::sysDescr.0 = STRING: Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(19)EA1c, RELEASE SOFTWARE (fc2)
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Tue 03-Feb-04 09:38 by yenanh

iPhone: Macro photos - Do you want to shoot great looking macro photos with your iphone or ipod touch?

http://osxdaily.com/2012/03/12/iphone-camera-macro-lens-water-drop/

Check out the page if you're interested what kind of macro photos are possible by applying a single droplet of water to your iPhone lens. Just amazing! 

The pictures are really nice.

They also link to an article from scientific american, the ant with the led background is nice.

http://blogs.scientificamerican.com/compound-eye/2012/03/12/transform-your-iphone-into-a-microscope-just-add-water/

If you might be interested as I was, then you can search for the report of the team that they describe here.

There are many people that have tried it successfully with an iPad touch.

regex: match mac address

http://manoharbhattarai.wordpress.com/2012/02/17/regex-to-match-mac-address/

ifconfig eth0 | egrep –-only-matching ‘(([0-9A-Fa-f]{2}[-:]){5}[0-9A-Fa-f]{2})|(([0-9A-Fa-f]{4}\.){2}[0-9A-Fa-f]{4})’

Education: Khan Academy on iPad; just marvelous!!

What a wonderful addition to the iPad, the khan academy iPad app.

My kids love to earn meteorites, moons and the like. Usually they don't wanna watch a video in full length but just go and try and excel. I think khan academy should start investigating some behavior analysis and just float in some info and provide some subtle links to parts of a video.

The other big hope is that there will be soon more languages available as their mother tongue is not english. But they still like to work with it and they have me to support them when necessary.

Hopefully they make a version where you'll be able to practice from the iPad using finger input! And maybe at one point they will make available the tree of knowledge to be used from the iPad app!

Happy education.

linux: rpm -qa --last | less or head #useful command

rpm -qa --last | head

show me the last installed rpm packages.

Gadget Watch: Kensignton WiDrive (16GB $49, 32 $94)

Just appeared in on of the local markets, a 16GB and 32GB Kingston Wi-Drive. 16GB at $49 sounds a bit expensive, since the current price of an USB stick for 32GB is $21.

This is definitely something to watch, since I run always out of space on any iDevice except not the 64GB Model, which is just to pricey.

The package does not mention a/b/g/n or any indication about battery life. Maybe it is extensible with a micro sd card? Will have to check at one point.

Current watch list:   

•  3G/Wireless MIMO router with SD Card slot, $110
• Wi-Drive 16GB at $49

What purpose? Movies, TV Series and PDF documents. Which player would be able to make use of it?

Does someone have some experience with it?