This is Warren Kwok's Internet note pad, electronic diary, online rubbish journal, whatever you might name it ! It is an archive of my random thoughts in a chronological order. I am not good at reporting boring things and change them to lively. If you find this blog boring, sorry that it is your problem.
2011/12/26
Anonymous threatened to blackout the Internet
Anonymous has threatened to blackout the Internet if Stop Online Piracy Act is passed:
http://www.homelandsecuritynewswire.com/dr20111223-anonymous-threatens-internet-blackout-over-controversial-legislation
Some people might ask how can the entire Internet be blackouted. If the root zone can be taken down, all websites and emails in the world will disappear. It is not known if Anonymous will attack hundreds of root servers scattered around the globe.
2011/12/23
IPv6 address entry keyboard
There is no such code as double colon in ASCII standard. If IPv6 gains popularity, it might be desirable to include :: as special character in ASCII table.
2011/12/22
I own the IPv6 address prefix of 2002:ca51:fc74::/48 permanently
This is just a gimmick. For those who are familiar with IPv6 addressing, they have already recognized that 2002:ca51:fc74::/48 is 6to4 equivalent of IPv4 address 202.81.252.116. I have previously used this v4 address to access NRO and claim to administer the reverse lookup for the range 2002:ca51:fc74::/48. This is just a gimmick. For those who are familiar with IPv6 addressing, they have already recognized that 2002:ca51:fc74::/48 is the 6to4 equivalent of IPv4 address 202.81.252.116. I have previously used this v4 address to access NRO and claim to administer the reverse lookup for the range 2002:ca51:fc74::/48.
If you do a "dig -x 2002:ca51:fc74::1", my v6 nameserver will give you an answer saying it is v6-mail.com.
2011/12/21
DHCPv6 in Lion
2011/12/16
Code of ethics for war-driving
Our team note that people are very concerned about privacy issue as a result of Google's unethical capture of WiFi data all over the world. We ask all participants to sign a statement on code of ethics which include no privacy intrusion, no monitoring of payload, no connection to scanned WiFi access points and all data must be destroyed after statistical analysis. As a further step to ensure no network connection, all team members must have TCP/IP protocols in their notebook PC disabled. We will check against each other such settings to ensure a high level of integrity.
The planned Macao war-driving by WTIA-PISA in September 2011 was banned by the Macao Government due to privacy issue stirred up by Google.
2011/12/13
ITVoice 2012
As usual, Charles Mok is again the King of the IT Sub-sector. He harvested 1466 votes, 218 votes more than he got in 2006.
2011/12/11
IPv6 address input keyboard
The keys of A-F plus colon, double colon and slash keys which are packed together adjacent to numeric keys is very handy for input of IPv6 addresses and prefix lengths. This keyboard should have been developed some years ago but not until now.
2011/12/09
Server no reboot for 805 days
Damn it, my goal of no server reboot for 1000 days just crashed.
2011/12/06
Hong Kong WiFi Security Index
2011/12/04
In-flight WiFi service
2011/11/30
HK Government’s IPv6 NTP Server at time.hko.hk
After many hours of testing and troubleshooting, we were sure that there was a bug in the firmware of the new atomic clock system which affected v6 network connectivity. However, we applied a temporary fix to make things work in a stable manner. The system could be accessed now.
I like to thank colleagues of CUHK, OGCIO and OFTA for helping the end-to-end testing and fault-finding in the past 3 days.
2011/11/27
D-LINK DIR-655 IPv6 home router
2011/11/25
The last IPv4 address in the world is 223.255.254.254
2011/11/22
vistumbler
I have found the solution. Vistumbler is another WiFi sniffer that supports Windows 7. The captured log can be saved in CSV format for analysis by excel. I will definitely use vistumbler in the coming war driving exercise.
2011/11/21
TP-LINK TL-WN822N 802.11n client
Yesterday, I decided to buy another one either for backup difference or for use in other desktop PCs. This is the best WiFi client I have ever used.
2011/11/20
WiFi Hopper only available in 32-bit Windows XP
2011/11/19
Postfix greylisting
2011/11/17
Hurricane Electric's 10G link at HKIX
http://www.marketwatch.com/story/hurricane-electric-announces-significant-global-upgrade-of-peering-bandwidth-2011-11-16
This really helps me a lot as I am using 6in4 tunnel of Hurricane Electric to bridge to the IPv6 Internet. After the upgrade, I tested that my IPv6 connections to overseas is at 8Mbps while the speed of connection to HK6IX is 91 Mbps. Actually, the connection is limited by my 100M network interface card and the Ethernet switch of my serving ISP.
Thanks, Hurricane Electric.
2011/11/08
Interesting picture
In fact, both are not moving. But if we look at them together at the same time, we have the illusion that they are moving.
2011/11/04
Can MAC address filter circumvent WEP cracking
The answer is No. MAC address filters are useless because MAC addresses are broadcast over air. When a legitimate client is connected to a WEP AP, a hacker can use hacking tools to discover the MAC address. He then clones the MAC address to his devices and then proceed to crack the WEP key. To reinforce my saying, I have taken a photo from a Linux machine running spoonweb. In the photo below, the MAC address of a connecting client is shown.
2011/10/30
Android phone failed to sync gmail
After investigation, I noted that my phone had the date set to 1 Jan 2000. Shit, auto-sync requires accurate time information on the terminal devices. After changing the date properly, everything was restored.
A good learning experience and exercise.
2011/10/16
In memory of Dennis Ritchie, Father of Unix
I was addicted to Unix in 1992 but only got my first reference book in 1994. As my appreciation to Dennis Ritchie, Father of Unix, I shall keep this book for the rest of my life.
2011/10/11
Blackberry outage in three continents
http://edition.cnn.com/2011/10/10/tech/mobile/blackberry-outage/index.html
Millions of users were affected.
As usual, RIM will never disclose the root of the failure using the excuse that RIM's network is based on a proprietary design and it needs to keep its network design and architecture confidential.
Though Asia was not affected in the incident yesterday, we can not be sure we get the same luck next time.
2011/10/04
iPhone 5 can not support 4G LTE
2011/10/02
IPv6 Speed Test
The speed tests done today were the best I have ever conducted. The overseas IPv4 and IPv6 connection speeds were almost the same at around 4.5 Mbps. This speed is sufficient for DVD-quality full screen video.
2011/10/01
gogoclient on WiFi
I note that there is a new version of Gogoclient which supports DS-Lite. I will download and try it.
2011/09/17
sharepod to replace iTunes
Another headache of iTunes is that if some songs in a PC's folder are inadvertently deleted, iTunes attempts to delete the same songs in ipod because of auto-sync. No such hassle in sharepod.
The only shortcoming is that I have to connect ipod to sharepod if I want to listen to music through my PC.
2011/09/12
25GB Cloud Storage
Doesn't sound much increase in storage capacity if one is using desktop or notebook. However, the cloud storage is accessible by iPhone and Android and this feature is very significant since smartphones do not come with hard drive.
The speed of access is a bit slow which can not be compared to accessing a local hard drive. The transfer of files is not aided by encryption. If this option is available, it makes access even slower. However, the experience of commercial paid cloud storage should be much better and encryption is a MUST.
2011/09/11
watching Youtube freezed after installing Windows 7 SP1
2011/09/08
Shall name-based virtal hosting be used in a web server even only a single website is hosted on the IP address
2011/09/05
Multiple SSL websites on a single IP address
There is now a tool to test if browsers can support SNI in the TLS handshake:
https://sni.velox.ch/
During the test, I noticed IE8 prompted an error message of invalid certificate, I just pressed the continue browsing button and I saw more details about IE failure.
What I observed is that the current version of Firefox, Chrome and Safari are capable of SNI while IE still lacks this function. On server side, I track that Microsoft IIS 7.5 is not able to do this SNI thing, but Microsoft has committed to make it in the next version. For browsers in smartphones, I can not test one by one since there are so many different packages.
This is just a bit of development. There is a long way to go before a single IP address can support multiple SSL websites on all different platforms while some browsers might still fall behind.
2011/09/03
Apache Killer killed
All system administrators should be relaxed now. The most devastating bug in the history of the open source community has been eliminated.
2011/08/29
Apache Killer again
This is sound and reasonable and so I decided to follow the approach.
2011/08/28
two partitions in ASUS notebook
2011/08/27
Rescue Windows XP Again
2011/08/26
Apache Killer
http://mail-archives.apache.org/mod_mbox/httpd-announce/201108.mbox/%3C20110824161640.122D387DD@minotaur.apache.org%3E
This bug exploits Apache's flaw in handling the RANGE field in HTTP request header. By sending a crafted request with a large number of fields within the Range header, the attacker is amplifying the request as each byte range field forces Apache to make separate copies of the requested resource which eventually consumes all CPU and memory resources.
The bad news is that system administrators need to wait for another 48 hours for Apache Foundation to release the patches. In the mean time, they can apply interim measures such as not allowing the use of Range headers.
This bug was first found in 2007. Wonder why Apache Foundation did not pay attention to it.
2011/08/19
XP Security 2012 Malware
2 hours were spent to remove the malware by using malwarebytes to scan the whole hard disk. Next, the failure of running executable files was due to corruption of .exe file association in the registry. Running the Windows File Association Fixes for .exe extension would bring the machine back to normal.
This is a deadly malware since it kills browser function and disable all executable programmes. I guess I would not have contracted the malware if I were using Chrome for web browsing.
2011/08/13
HKEx attack incident
What the fuck has Hong Kong learnt from the HKEx attack case.
TSIG-based zone transfer and clock sync
That is why the master and slave must sync with a NTP server in a more frequent manner.
2011/07/27
No flash for 64-bit IE9
2011/07/25
FTP Error "500 - Illegal port command"
On careful reading the TP-Link manual, there is a security feature called FTP ALG which allows ftp traversal over NAT. Without enabling FTP ALG, ftp is destined to fail because the client provides a private IP address and a port number to the FTP server but somehow, the port number is changed by the NAT device. FTP ALG ensures that the NATed port number and the ftp data port number initiated by the client are kept in a one-to-one mapping state table.
This is another example of NAT breaking end-to-end connectivity. Similar ALGs are also needed for SIP and H.323. NAT only brings troubles to the networked Internet world and it should be dropped as soon as practicable.
2011/07/22
laptop with two display cards
2011/07/13
Which company made the first IPv6-compatible product ?
2011/07/12
Good and bad news about MAC OSX 10.7 on IPv6
Apple should have given out DHCPv6 client program to its MAC OSX a long time ago. What is the diffculty !!
2011/07/11
.hk SOA Serial Number
Usually, some TLDs (example .se) prefer to use the yyyymmddss format like 2011071103 or the Unix time format like 1310367702 (example .com and .net) which can be readily translated back to 11 July 2011, 7 hours 3 min and 12 seconds.
It will be an interesting task to study if SOA serial number format adopted by .hk could yield technical and/or operational merits as compared to other traditional formats.
2011/07/07
An ISP uses 6to4 tunnel to serve as v6 DNS resolver
The extra path to a 6to4 gateway introduces delay and there is no acceptable guarantee of service. Bearing in mind the WTT 200M native IPv6 service is for corporate users, how comes WTT offers a lower class service for not providing truly v4/v6 DNS resolvers.
I think ISPs in Hong Kong should be careful not to rely on tunnels as part of its native v6 service
2011/07/06
1.8 GHz or 2.4 GHz cordless phone
I believe I have made a smart choice in not purchasing a 2.4 GHz cordless phone.
2011/07/05
Remove Joomla icon
2011/07/01
Stratum 1 or 2 NTP
2011/06/23
Another way to look at IPv6 address space
I like to try to think of it in a dynamic way. If 1 million /64 subnets are assigned to people or electronic devices every second, then it would take 584,942 years to make the address space completely exhausted ((2 ^64 / (365*24*3600*10^6)). This is longer than the history of human civilization. Will IPv6 addresses be completely exhausted ? No way, no need to worry.
2011/06/22
ZSK rollover in Top Level Domains
com. – 1 weeks
org. – 3 weeks
asia. – 3 weeks
my. – 3 months
th. – 1 week
I can not locate any RFC related to this technical aspect. Intuitively, from a security angle, I incline to think 3 months is too long while 1 week ZSK will introduce heavy workload on the name servers. I tend to think 3 – 4 weeks is the best option.
2011/06/21
Assignment of two IPv6 addresses
Likewise, if a supermarket sells poor quality beef to customers, I have no choice but to assign this IPv6 address to the supermarket - 2001::bad:beef
2011/06/19
ipod battery
2011/06/18
Good news after World IPv6 Day
2011/06/17
APNIC’s new logo is fantastic
Well-done, APNIC.
2011/06/16
Chromebook disappointed me totally
Chromebook is no more than a thin client with the difference that the underlying OS is the Chrome browser. There might be arguments that it offers the benefits of fast boot-up (in a matter of less than 10 seconds), longer battery use, and better security (no virus software, sandboxing approach to protect end users). But are these benefits justified for the high cost ? I would rather add some money buy an ipad2 (US$629) or Android 3.0 tablet which offer me more functionalities, applications and computing powers.
2011/06/15
Windows 7 handling RA and RDNSS
Actually, I had some experience on a different scenario. During APRICOT-APAN 2011, I used a IPv6 only network and the v6 address assigned to my Window 7 machine was quite like auto-configuration but there was the assignment of v6 DNS resolvers. I was mindful that Windows 7 could not support RA with RDNSS and the question was where come the assignment of v6 DNS resolvers. The answer was that the network was using a DHCPv6 to assign DNS resolvers while there was a RADVD to accomplish the task of auto-config IPv6 address for clients. Up to this point, I should fire a bullet at Microsoft for not releasing patches to make RA working with RDNSS. This would save the unnecessary provision of a DHCPv6 server.
Luckily, I still keep a picture of the configuration for reference which is posted below.
2011/06/14
RFC 6106 - IPv6 Router Advertisement Options for DNS Configuration
In Linux, RADVD can have fully function of SLACC plus RDNSS. Just look at the following few lines in the config file :
interface name {
list of interface specific options
list of prefix definitions
list of clients (IPv6 addresses) to advertise to
list of route definitions
list of RDNSS definitions
};
RDNSS ip [ip] [ip] {
list of rdnss specific options
};
Just wonder if I have the time to configue one set of RADVD with RDNSS and then test the allocation of prefix and DNS resolvers to Windows 7 machines.
2011/06/13
Kidney for an ipad2
In China, a 17-year student sold his kidney for an ipad2. The news and interview can be found in the URL
http://www.wupia.com/2011/06/a-high-school-student-in-china-sold-his-kidney-for-an-ipad-2/
Apple will definitely release ipad 3, ipad 4, ipad 5 and so on. I am afraid that after two more rounds, the 17-year student has no more internal organs to sell.
My dear Almighty God, please tell me the meaning and value of life. Can human beings trade their internal organs with electronic devices ?
2011/06/12
Which iOS supports IPv6
Can readers please correct me if I am wrong. Thank you.
2011/06/11
World IPv6 Day is over, what’s next ?
2011/06/10
LISP Reliability Issue
http://warrenkwok.blogspot.com/2011/05/facebook-adopts-lisp-to-roll-out-ipv6.html
There is a degradation in reliability as compared to a single router. Assuming each of the three routers has a reliability of 99.9 %, if cascaded together, the overall reliability of the routing system drops to 99.7 %. The down time will be increased from 8.76 hours to 26.28 hours in a year.
Can Facebook and other early LISP adopters accept the degradation ?
2011/06/09
No IE9 for Windows XP
Isn't it fair ? Microsoft does not offer IE 9 for XP. I have tried IE9 on Windows 7. It is fast and has a good performance in loading grpahics and gives a very streamlined operation in tabbed browsing.
Frankly, we do not have many choice. IE 8 is buggy. Firefox now only gets bigger but also gets slower. Chrome has a cache problem especially when I post comments on other people's status on facebook. I urge Microsoft to re-consider developing an IE 9 version for current XP users.
2011/06/08
Absolutey amazing. All big content providers and organisations are on IPv6 today.
[warren@dnssec ~]# dig aaaa www.facebook.com +short
2620:0:1c18:0:face:b00c:0:3
[warren@dnssec ~]# dig aaaa www.google.com +short
http://www.l.google.com/.
2404:6800:8002::69
[warren@dnssec ~]# dig aaaa www.yahoo.com +short
fpfd.wa1.b.yahoo.com.
2001:4998:f011:1fe::3000
2001:4998:f011:1fe::3001
[warren@dnssec ~]# dig aaaa www.bing.com +short
ipv6.search.ms.com.edgesuite.net.
a1877.dscb.akamai.net.
2600:140e:3::3cfe:af33
2600:140e:3::3cfe:af38
[warren@dnssec ~]# dig aaaa www.xbox.com +short
http://www.gtm.xbox.com/.
msxbwsd.vo.llnwd.net.
2402:6800:720:11:230:48ff:fe8d:aa6e
2402:6800:720:11:230:48ff:fe8d:a992
[warren@dnssec ~]# dig aaaa www.cisco.com +short
v6day.cisco.com.akadns.net.
geo-v6day.cisco.com.akadns.net.
cisco-redir.v6day.akadns.net.
cisco.v6day.akadns.net.
2001:420:80:1:c:15c0:d06:f00d
[warren@dnssec ~]# dig aaaa www.youtube.com +short
youtube-ui.l.google.com.
2404:6800:8002::5b
2011/06/06
web-based v6 email autoreply tool
2011/06/05
Failed the test as a Hong Kong IPv6 website
The reason was that the ping rtt time was about 290 msec from a Hong Kong v6 node and the acceptance criterion is to have rtt < 10 msec. The site rides on a overseas proxy somewhere in Netherlands.
I have no bad feeling at all. The accepting criterion is fair and reasonable.
2011/06/04
Enable v6 access by web proxy approach
http://ipv6proxy.prolocation.net/
This is a web proxy approach. A website only has to enable AAAA record pointing to the v6 leg of the proxy server which is 2a00:d00:ff:131:94:228:131:131. When the proxy receives the http headers, it knows the domains name and can get the web content from v4 network and pass to the v6 visiting clients.
However, there are some limitations. No doubt end-to-end connectivity is broken so I can readily imagine that HTTPS and VPN can not be supported.
2011/06/03
CUHK opens its v6 Stratum 2 NTP Server for public
The Hong Kong Observatory will provide its v6 NTP Server by the end of 2011. For the time being, I still have to use the one offered by CUHK.
[warren@dnssec ~]# /usr/sbin/ntpdate -6 ntp.cuhk.edu.hk
3 Jun 21:09:58 ntpdate[31742]: adjust time server 2405:3000:3:b0:137:189:11:149 offset 0.008007 sec
[warren@dnssec ~]# /usr/sbin/ntpdate -6 ntp.cuhk.edu.hk
3 Jun 21:09:59 ntpdate[31743]: adjust time server 2405:3000:3:b0:137:189:11:149 offset 0.007619 sec
[warren@dnssec ~]# /usr/sbin/ntpdate -6 ntp.cuhk.edu.hk
3 Jun 21:09:59 ntpdate[31744]: adjust time server 2405:3000:3:b0:137:189:11:149 offset 0.007238 sec
[warren@dnssec ~]# /usr/sbin/ntpdate -6 ntp.cuhk.edu.hk
3 Jun 21:10:00 ntpdate[31745]: adjust time server 2405:3000:3:b0:137:189:11:149 offset 0.006820 sec
[warren@dnssec ~]# /usr/sbin/ntpdate -6 ntp.cuhk.edu.hk
3 Jun 21:10:02 ntpdate[31751]: adjust time server 2405:3000:3:b0:137:189:11:149 offset 0.005666 sec
[warren@dnssec ~]#
2011/06/02
What benefits of IPv6 apart from large address space and elimination of NAT
The protocol IPv6 is a boring thing. Frankly, I have no confidence to turn it into something interesting !
2011/06/01
SOA minimum to deal with the large number of queries for AAAA record for a website which only runs on IPv4
It is important to set the SOA minimum to a higher value like 1 hour (3600 sec) for protecting the authoritative name servers from overloading. As more and more users change to use Windows 7, the DNS traffic for asking non-existing AAAA record will boost. All DNS administrators have a role to play for the smooth and steady operations of the Internet.
2011/05/31
Facebook adopts LISP to roll out IPv6 Service
LISP (Locater/Identifier Separation Protocol) is amazing. It redefines the relationship between end-point, IP address and router. The IP address assigned to an end-point is simply an identifier and the router is a locator. If the Locator can be spilt into egress and ingress network elements and with the addition of one to one single v4-v6 mapping, then all existing v4 platforms can server v6. Facebook can then save hardware cost, avoid v4 and v6 software clash and most importantly achieve quick roll out of IPv6 service.
There are two questions remaining. First can LISP handle huge traffic and second how can resilience be built into LISP.
No matter how, LISP is a promising new technology which content providers should pay attention to.
2011/05/29
IPv6 Cache Servers + IPv4 Forwarders
2011/05/28
A message to all my IT friends in Facebook
"Dear XXX,
You are in the IT field. Are you a member of iProA ? If so, I am not your friend anymore. I ask this because most of my friends are in the IT Sector. Some of them turn to DAB and iProA to get social and political advantages. I want to make sure all my IT friends are clean from DAB poison.
Sorry to bother you and ask you."
All replies so far are positive.
2011/05/27
OpenDNS offers IPv6 resolvers
I definitely have the need to use IPv6 resolvers for network configurations, testing and troubleshooting. A big hand to OpenDNS.
2011/05/26
Impact of World IPv6 Day to Hong Kong
2011/05/25
Empty a file
#cat /dev/null > dnssec.log
Another common usage is "echo -n > dnssec.log" .
My way of clearing all content of a file is odd as I am using tail :
#tail dnssec.log > dnssec.log
Interesting, I forget how, where and when I learnt this crazy command. Indeed, I don't quite understand how printing some last lines of a file on screen and then pipe to the file itself can actually clear all the content.
2011/05/24
If it is not CISSP, it may not be the best fit
2011/05/23
Facebook Internet email addresses are easy to harvest
www.facebook.com/peter.chan
www.facebook.com/andy.chan
www.facebook.com/david.lee
All are success. That means, I have harvested three valid email addresses @facebook.com.
Without knowing what facebook can do in anti-spam, it gives me no choice but to stop the email account @facebook.com by setting the privacy preferences as not to receive any Internet email messages. The return error message below verified that things work up to my expectation:
***** Quote *****
Final-Recipient: rfc822; warren.kwok@facebook.com
Diagnostic-Code: smtp; 550 5.1.1 RCP-P2 http://postmaster.facebook.com/response_codes?ip=202.81.252.116#rcp Refused due to recipient preferences
Action: failed
Last-Attempt-Date: Sun, 22 May 2011 18:37:56 -0700
Status: 5.1.1
***** End of quote *****
2011/05/21
Control-Enter shortcut key in IE Browser
But what happen to my IE. If I do the same on IE, the address bar will become "www.cnn.com.tw". Hey, the crazy thing is ".tw". It is because my IE browser is a Taiwanese version. I don’t understand why Microsoft is so crazy to insert ".tw" when dealing with the most common CTRL-ENTER shortcut when the IE browser is a Taiwanese version. I am not going to change my IE to English version just because of this crazy flaw. I must say I hate the foolish mindset of Microsoft software people.
2011/05/20
chksig - DNSSEC tool for Windows
T
This tool is bundled with another copy which work on DOS command-line interface. Using this tool in both the GUI mode and command-line mode are interesting.
2011/05/19
nslookup should be phased out
Just ask yourself a simple question, can nslookup tell if a resolver has successfully verified the signature of a queried name record if the zone being interrogated is DNSSEC-signed.
2011/05/18
103/8
103/8 is the final /8 block and when allocation of 103 prefix is started, APNIC has already activated the final /8 policy. The final /8 policy only allows existing or new members to get /22 (1024) IPv4 addresses which can only be used to build v4<->v6 transition systems for supporting IPv6 networks to reach IPv4 networks. This banner might stay in APNIC website for up to 5 years. Its purpose is to remind ISPs and corporations that they should move to IPv6 by now.
The consumption of v4 addresses in AP Region is alarming. On Feb 2011, IANA allocated the 39/8 and 106/8 to APNIC. These two blocks were depleted in early April 2011 prompting APNIC to activate the final /8 policy for the last block.