Sunday, May 31, 2009

using the phone as a modem

Followed the excellent article at pdagold to connect to use the phone as a modem. Basically it requires that I start the Modem Link software on the phone, "Activate" on the phone, and use the provided dialler with the appropriate APN. Bluetooth modem is proving to be more difficult, will try it later.

Speed tests - 48 kbps using McAfee's speed test, and also by manually counting the number of bytes.

As you can see, the testing involved around 2 MB of data transfer, lasting around a minute more for a total of around 7 minutes, and this cost approx Rs. 12.

Thursday, May 28, 2009

DNS requests not resolving

We faced a strange problem on fs3 of DNS requests not resolving - nslookup would complain that even the default dns server could not be contacted and would time out after 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Can't find server name for address x.y.z.p: Timed out
Default Server: UnKnown
Googling gave many hits on configuring the dns service properly, and advice to run
ipconfig /registerdns
All these didn't work - finally the issue turned out to be a firewall problem after all: TCP/IP filtering was turned on, and ALL UDP packets were being blocked. TCP/IP Properties -> Advanced -> Options tab, TCP-IP filtering Properties, Changed radio-buttons to Permit All for UDP Ports and Protocols. That solved the problem.

SPF restored

No wonder the SPF was being shown as bad by the tools in my previous post - whoever shifted our domain to the new dns servers had also forgotten the spf records in addition to many cnames. Restored it today.

Wednesday, May 27, 2009

Signing emails with DKIM

Yahoo once again started rejecting mails from our mail server. I wanted to title this post "Yahoo mail admins need to grow up" but then thought better of it. After filling in their bulk sender form for the third time, decided to enter their Complaint Feedback Loop programme. Had to implement DKIM first, so headed over to howtoforge after googling. Test mechanisms were in the centos setup page and the DNS setup required a request to our ISP. Then signed up for the complaint feedback loop, and the next day got 3 'complaints' - these 3 guys marked our mail as spam to cause yahoo to block 3000 of our subscribers.

In case the howtoforge articles vanish, here's the gist:
sudo apt-get install dkim-filter
sudo mkdir /var/dkim-filter
cd /var/dkim-filter
sudo openssl genrsa -out private.key 1024
sudo openssl rsa -in private.key -out public.key -pubout -outform PEM
sudo vim /etc/dkim-filter.conf
Here, un-comment the following, with the appropriate domain name. The selector can be anything, only remember to set the same selector name in dns. Relevant dkim-filter.conf settings:
# Log to syslog
Syslog yes
# Required to use local socket with MTAs that access the socket as a non-
# privileged user (e.g. Postfix)
#UMask 002

# Sign for with key in /etc/mail/dkim.key using
# selector '2007' (e.g.
KeyFile /var/dkim-filter/private.key
Selector mail

# Common settings. See dkim-filter.conf(5) for more information.
AutoRestart no
Background yes
Canonicalization simple
DNSTimeout 5
Mode sv
SignatureAlgorithm rsa-sha256
SubDomains no
UseSSPDeny no
X-Header no
Actually setting the X-header to yes is useful for initial debugging - then, checking the headers shows you right away if the milter is working. (Milter = Mail API Filter, from sendmail-speak). Then
sudo /etc/init.d/dkim-filter start
sudo vi /etc/postfix/
to add the following lines to the end,
milter_default_action = accept
milter_protocol = 2
smtpd_milters = inet:localhost:8891
non_smtpd_milters = inet:localhost:8891
And then finally restart with
sudo /etc/init.d/postfix restart
The DNS record to be set is of the form
mail._domainkey.DOMAIN.TLD. IN TXT "k=rsa; t=y; p=MIGfKh1FC.....bfQIDAQAB"
where mail is the selector, DOMAIN.TLD should be your domain name and the p=is the key from /var/dkim-filter/public.key

Once the dns propagates, you can check by sending email to yahoo or gmail - gmail shows as "signed by" when you click show details. lists some test tools - some of them are a bit flaky. I got dkim=pass from but reported my SPF as bad - I thought it was working.

Wednesday, May 13, 2009

add Google contacts to windows mobile without using Outlook

Googling got this link which pointed to this great solution.

1. Install PIM Backup
2. Change the extension of the Outlook formatted .csv file to .csc
3. Zip the file and change the extension of the .zip file to .pib, copy the pib file to the mobile.
4. Run the PIM backup app on the windows mobile, and choose the Restore option, browsing to the .pib file above. It gives the option to allow duplicates or update existing contacts and so on.

Here actually the third option is what I selected - add contacts and update old etc. BTW the screenshot was taken with MyMobileR using which you can control your mobile from your PC.

Saturday, May 09, 2009

more with the QTEK mobile

Posting this with the QTEK mobile with wifi at home. Wifi at work working as of now only in "Open" mode and not WEP or WPA. But probably will have some workaround. Home wifi needed freebase to make the SSID broadcast - it couldn't connect with SSID hidden. Saw some google results about WM6 having that feature, but this one is WM5 and can't. Skype for WM was disappointing - 10 MB download, and the sound was stuttering on wifi. Fring looks much more promising, and feature packed too. Skyfire looks really good, and streams youtube videos without buffering over our 256 k connection.

Wednesday, May 06, 2009

QTEK 9100 mobile

Set up the smartphone to use wifi at home, but not yet working at PSN with the Airport - probably the hidden SSID is causing the problem for Windows Mobile 5. Infrared works fine with the Toshiba PDA, but transfers to the laptop @ S3 were not going through. Bluetooth also the same. Set up with mobireader total commander etc. Will set up skype as and when the wifi is operational.

GPRS setup on Airtel was simple enough, but had to call customer care.

Start -> Settings -> Connections tab -> Connections -> Advanced tab -> Select Networks
Here, Programs that connect to the internet should connect using 'My ISP name'

Start -> Settings -> Connections tab -> Connections -> Tasks tab
under 'My ISP name', manage existing connections -> Modem should be Cellular line (GPRS) and the apn name or access point name should be, username and password to be left blank.

Charges are currently 30 paise for 50 kB.