String around my finger
A 'blog to remember things I found.

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I work for NIS ITS Monash University Australia.

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• security 1
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• windows 3

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BitTorrent

Tim pointed me to an excellent article on Wikipedia describing BitTorrent. See also their page on Peer-to-peer in general.

Somewhere else (???) described BitTorrent as being different from other peer-to-peer applications because there is no inbuilt method for publishing, or searching for metadata. Publishing (announcing to the world that you have some files with particular names / descriptions / sizes / checksums ) and searching (the world being able to find the file you want and how to get it) are done using other tools such as Web servers, e-mail, or even embeded into games.

In some file-sharing schemes, a large number of users get together and share a number of files that is 10s, 100s or 1000s of the number of users. In contrast, with BitTorrent, a number (between 2 and 100,000) of users obtain the .torrent metadata for a single file (or indivisible bundle of files), and then get together in a specially-purposed swarm to spread just that file to all of them.

Comparing BitTorrent to normal Web operations, I think BitTorrent is most like a dynamic distributed caching proxy server cloud. You can't tell whether a file came from the original site, or from a proxy -- a local proxy, your ISP's proxy, a parent or peer of proxy the proxy you thought you were using, a front-end reverse proxy, a load balancer, ... Normal Web proxy networks are general purpose and need to be statically configured. BitTorrent proxy clouds are single file, highly dynamic and self-organising (with hints from the tracker).

A BitTorrent proxy cloud operates differently in that a client will up/download parts of the a file (and cryptographically check those parts), rather than a Web proxy which likes to deal in whole files (and blindly trusts the received content).

Brian Dessent writes

It takes a great deal of bandwidth and server resources to distribute files that are large or very popular, or both. The concept of mirrors partially addresses this shortcoming by distributing the load across multiple servers. But it requires a lot of coordination and effort to set up an efficient network of mirrors, and it's usually only feasible for the busiest of sites. ...

BitTorrent is closest to Usenet, in my opinion. It is best suited to newer files, of which a number of people have interest in.

PS. Microsoft are working on something similar called Avalanche

The code-named research project "Avalanche" studies how to enable a cost effective, internet scalable and very fast file distribution solution (e.g. for TV on-demand, patches, software distribution). Such an approach leverages desktop PCs to aid in the distribution process, relieving congested servers and network links from most of the traffic.

Will peer-to-peer be banned if Microsoft provide it and want you to use it? (Windows File and Print is peer-to-peer already.)

[ /software | # ]

iPodder

"The cross-platform podcast receiver"

If you want to listen to internet audio programs (podcasts) but can't when they are scheduled, this program is for you.

It allows users to select and download shows and music and to play whenever they want on their iPods, portable digital media players, or computers automatically, after specifying which music or shows they want to listen to.

See definition of Podcasting at Wikipedia, along with RSS 2.0, ATOM etc links. Also see Payloads for RSS where it all started.

Downloaded iPodder-linux-2.1.tar.bz2 from here,

Installing iPodder into Fedora Core 3 Mini-HOWTO

Installed. it. It put files into /opt/iPodder and a symlink into /usr/bin -- hardly my favorite places. It also needs a

# chmod +r /opt/iPodder/ipodder/players.py

[ /software | # ]

EtherBoot

"Etherboot is a software package for creating ROM images that can download code over an Ethernet network to be executed on an x86 computer. Many network adapters have a socket where a ROM chip can be installed. Etherboot is code that can be put in such a ROM."

We will be using Etherboot from floppy. The "Boot Rom" image is only 16 KB in size, initialises the Ethernet card, does a DHCP to get the PC's network config, and TFTP IP address and file name to download a full boot image (kernel or PXE) ...

Although the SMC EtherCard 8216C uses the 83C790QF chip, the obvious answer doesn't work. Get "probing pci / probing isa / [SMC9000] / <sleep> / ..." repeat.

As per this vote, we need a "wd" boot rom, and DHCP options

option option-128 e4:45:74:68:00:00;
option option-129 "NIC=smc-ultra IO=0x300 IRQ=10

These cards have 4 jumpers for fixed settings, and one for soft configuration. I found my driver disks I used for configuring WD 8003EB cards many years ago -- they were on 5.25" floppies !!

The current ROM-o-matic.net doesn't contain a "wd" image. Selecting "sn8390:wd" creates a "eb-5.2.6-ns8390.zdsk" which doesn't work.

Using version 5.2.2 and selecting "wd" creates a "eb-5.2.2-wd.zdsk" which DHCPs, TFTPs, boots, NFS mounts, but has problems at the "Doing the pivot_root" stage. "tcpdump" shows lots of UDP fragments that don't get re-assembled.

Using an Intel EtherExpress Pro/100 with a "eb-5.2.6-eepro100.zdsk" image works very well!!

[ /software | # ]

Managing Software Raid

http://www.cse.unsw.edu.au/~neilb/source/mdadm/

mdadm is a program that can be used to create, manage, and monitor MD (Multiple Devices) devices. As such it provides a similar set of functionality to the raidtools packages.

mdadm can provide information about your arrays (through Query, Detail, and Examine) that raidtools cannot.

MANAGE MODE Usage: mdadm device options... devices...

This usage will allow individual devices in an array to be failed, removed or added. It is possible to perform multiple operations with on command. For example:

mdadm /dev/md0 -f /dev/hda1 -r /dev/hda1 -a /dev/hda1

will firstly mark /dev/hda1 as faulty in /dev/md0 and will then remove it from the array and finally add it back in as a spare. However only one md array can be affected by a single command.

If you're using the /proc filesystem, /proc/mdstat lists all active md devices with information about them. mdadm uses this to find arrays when --scan is given in Misc mode, and to monitor array reconstruction on Monitor mode.

For Mandrake: http://rpms.mandrakeclub.com/rpms/mandrake/official/10.1/i586/media/main/mdadm-1.7.0-3mdk.i586.html

[ /software | # ]

Samba Group Policies

http://freshmeat.net/projects/karoshi/
Karoshi is a point and click server setup for secondary schools running Mandrake Linux 10 on the servers and Windows 2000/XP on the clients. It provides a set of point and click server configurations for a primary domain controller, a file server for students' work, a print server with Web-based queue management, and a filtering and monitoring Internet proxy server.

Google search for: samba "group policy"

http://lists.samba.org/archive/samba/2004-September/093255.html
John Terpstra wrote:

See http://www.samba.org/samba/docs/Samba-Guide.pdf chapter 6. There is an example of how to configure a desktop profile with all policies enabled in a manner fully compatible with XPP and 2KP.

http://searchwin2000.techtarget.com/originalContent/0,289142,sid1_gci1005581,00.html
Vintela Group Policy (VGP) is a component to Vintela's Authentication Services (VAS) software. VAS 2.6, which is available today, is licensed per server and per Unix-enabled accounts in Active Directory. It costs $200 per server and starts at $25 per user account in a 10-user pack. VGP 1.0 pricing starts at $50 per server and $5 per user.

http://www.spinics.net/lists/samba/msg29036.html
Mike MacCana wrote:

A company called Nitrobit has a group policy implementation that works in conjunction with Samba and any LDAP server (though they use OpenLDAP in their examples). Editing is done using the MMC, policies are stored in the directory, and applied with a client app.

http://www.nitrobit.com/GroupPolicy.html

http://www.nitrobit.com/GroupPolicy.html
Our new software is now building the bridge: Microsoft Group Policy, which worked solely in the Microsoft Active Directory, can now be used within samba domains. With the help of group policies administrators can define their clients environment exactly the way it's needed for their work - and they can work with tools they know already from the Windows-world.

The nitrobit group policy-system consists of a client component which adapts the group policies to the single pc and an editor-environment to manage the complete group-policy-system.

The nitrobit group policy system can be used in two configurations. The basis configuration needs solely a network directory. The extended configuration, which enables software distribution, additionally requires an LDAP-Server. Different LDAP-Servers are being supported, one of them is the free Open LDAP-Server.

http://www.nitrobit.com/Downloads.html
Download documentation, and a 40-day Evaluation Version

[ /software | # ]

Unison

http://www.cis.upenn.edu/~bcpierce/unison/
Unison is a file-synchronization tool for Unix and Windows. It allows two replicas of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other.

Does two-way push-pull synchronization.

# If any new preferences are added by Unison (e.g. 'ignore'
# preferences added via the graphical UI), then store them in the
# file 'common' rathen than in the top-level preference file
addprefsto = common
 
# regexps specifying names and paths to ignore
ignore = Name temp.*
ignore = Name *~
ignore = Name .*~
ignore = Name *.o
ignore = Name *.tmp
 
ignore = Name lock
 
contactquietly = true
times = true

root = /
root = ssh://blowie4.its.monash.edu//
 
path = home/iso/
path = home/iso2/
path = home/local/in/
path = home/local/media/
path = var/cache/apt/archives/
ignore = Name partial
path = var/state/apt/lists/
include common

root = /home/blowie4/
root = ssh://blowie4.its.monash.edu//
 
path = etc/
ignore = Path etc/gconf
path = usr/local/
 
key = 1
 
include common

[ /software | # ]

interceptty
http://www.suspectclass.com/~sgifford/interceptty/
interceptty is a program that can sit between a real (or fake!) serial port and an application, recording any communications between the application and the device. It can also be used as a network serial server or client, to provide an emulated serial port connected to a program, and for various other tasks.

See examples described in man page http://www.suspectclass.com/~sgifford/interceptty/interceptty.html

[ /software | # ]

FCKeditor - the text editor for the Internet

http://www.fckeditor.net/
This HTML WYSIWYG text editor brings to the web many of the powerful functionalities of known desktop editors like Word. It's really lightweight and doesn't require any kind of installation in the client computer.

[ /software | # ]

TinyMCE

http://tinymce.moxiecode.com/
TinyMCE is a platform independent web based Javascript HTML WYSIWYG editor. It has the ability to convert HTML TEXTAREA fields or other HTML elements to editor instances.

[ /software | # ]

Mygnokii2/Gammu
http://www.mwiacek.com/gsm/soft/gammu.html
Command-line tools for Nokia (and other) phones (from http://www.gnokii.org/)

sms / phonebook / logos / ringtones / calendar / call functions / backup/restore SIM.

Supports various cables / BlueTooth / Infrared.

GUI is Wammu

[ /software | # ]

OpenOffice.org extras
http://www.oooforum.org/forum/viewtopic.php?t=7

http://fr.openoffice.org/Documentation/Gallery/indexgal.html
http://fr.openoffice.org/Documentation/Gallery/w_gallery-20040719.zip
collection of images

OO Extras
http://ooextras.sourceforge.net/downloads/english/index.php?tab=All
http://sourceforge.net/project/showfiles.php?group_id=53194
Some things. Doesn't look like very much.

http://documentation.openoffice.org/user_faq/various_topics/002.html
Differences between StarOffice and OpenOffice.org - Extensive Clip Art Gallery

[ /software | # ]

rrdcollect-remote
http://freshmeat.net/projects/rrdcollect-remote/
rrdcollect-remote is a Perl daemon that uses the rrdcollect ability to print RRD updates commands to its standard output to do updates from a remote machine using a persistent RSH or SSH connection.

looks interesting ...

[ /software | # ]

Dell slow after SP2
Last Words On Service Pack 2 "Slashdot"[http://it.slashdot.org/article.pl?sid=04/09/03/1842252&tid=201&tid=128] ZDNet is reporting that many Dell Inspiron users are reporting an extreme performance decrease since installing Windows XP SP2 .. roll back the processor driver.

"Dell Forum"[http://forums.us.dell.com/supportforums/board/message?board.id=sw_svcpacks&message.id=326&view=by_date_ascending&page=3] "P4"[http://forums.us.dell.com/supportforums/board/message?board.id=sw_svcpacks&message.id=326&view=by_date_ascending&page=4]

"Dell SP2 page"[http://support.dell.com/support/topics/global.aspx/support/kb/en/document?dn=1090448&c=us&l=en&s=gen&cs]

"WinXP Post SP2 TCP-IP Connection Speed Tweak"[http://www.winxpcentral.com/windowsxp/xpsp2speed.php]

[ /software | # ]

postfix-anti-UCE.txt

Jim Seymour's suggestions/examples for Postfix anti-UCE configuration. Which RBLs to trust etc

http://jimsun.linxnet.com/misc/postfix-anti-UCE.txt

[ /software | # ]

downlets

? extract images / movies from Web pages ?

http://sourceforge.net/projects/downlets/

[ /software | # ]

DiskOnKey

Windows-based Format Utility for HP Drive Key or DiskOnKey USB Device.

Make a USB key (or CF+USB adapetr) into a bootable device. Handy for booting floppy-less laptops into DOS mode.

http://h18007.www1.hp.com/support/files/hpcpqdt/us/download/20306.html

[ /software | # ]

munin

Munin is a tool for graphing all sorts of information about one or more servers and displaying it in a web interface. It uses the execellent RRDTool (written by Tobi Oetiker) and is written in Perl.

http://www.linpro.no/projects/munin/

[ /software | # ]