Blog CAPTCHA

I have recently received a lot of blog spam, most of which deal with medicine.  Presumably, the messages are generated by some automatic scripts and these spam messages disturb a lot of bloggers.  This leaves me no choice but to activate CAPTCHA verification.  I hate deleting spam messages manually one by one and I hope that with the use of CAPTCHA,  the number of blog spam can be reduced to a minimum.

ssh client on a tablet

So finally I have SSH terminal on a tablet.  I can do some less keyboard-intensive tasks such as checking logs and minor config changes.  It is Juice SSH client.  No need to root the tablet.

Change of IP address in Root Server D

Root Server D has changed its IP address on 3 Jan 2013. I have done my job to align with the change.  The file to change is "/var/named/chroot/var/named/named.ca".

The old IP address will retire in the next 6 months. Just wonder how many ISPs and network administrators have done their work diligently?

http://d.root-servers.org/

Google map offline

When I was in Dubai 2 months ago, I relied on Google Map to guide me from various Metro-stations and main streets to shopping malls and hotels.  This was done in online mode and sometimes the responses were slow if the connected 3G network was congested, not to mention the data usage charges.

I just discovered that Google Map offers offline cache though the  area is restricted to 10 miles x 10 miles for each cache map.  That would save me a lot of time and cost next time if I travel in another city.  Without delay, I have downloaded cached maps of Shenzhen, Macau, Zhuhai and Beijing.  It would be better to view  the offline maps in a 7-inch Android tablet than a small smartphone .  Google is very thoughtful.  Thanks.

Google public DNS can support DNSSEC

Google has completed a marvelous job. Its four public resolvers at "8.8.8.8", "8.8.4.4", "2001:4860:4860::8888" and "2001:4860:4860::8844" can now support DNSSEC and perform signature validation.

[warren@dnssec ~]# dig +dnssec ds icann.org @2001:4860:4860::8844 | grep ad
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
[warren@dnssec ~]# dig +dnssec ds icann.org @2001:4860:4860::8888 | grep ad
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
[warren@dnssec ~]# dig +dnssec ds icann.org @8.8.8.8 | grep ad
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
[warren@dnssec ~]# dig +dnssec ds icann.org @8.8.4.4 | grep ad
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1

My double thumb up to Google.