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by: Bernard Teo








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Bernard Teo
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Thu 29 Apr 2010

DNS Agent updated

Category : Technology/DNSAgent1dot0dot1.txt

Our server was not reachable for 5 hours last night. I only discovered it early this morning at 5.00 am when I woke up.

Turns out that at around midnight, our public IP address had a new lease of its IP address. So the IP address changed but DNS Agent, somehow, was not able to update dyndns.com with this latest IP address.

But why? It had been working very well for a couple of months already. By building our own dynamic DNS update mechanism, using DNS Agent, I'm able to update dyndns.com very quickly, restricting our downtime, whenever our public IP address changes, to not more than two minutes.

So why didn't it update dyndns.com this time? Turns out that there seems to be a change at dydns.com's dns server - it stopped responding to ping requests. I designed DNS Agent to ping the DNS Server to make sure it's alive before wasting time trying to contact a particular port. But some admins could turn on "stealth mode", like on our Macs, and make the server refuse to respond to ping requests. That looks what what happened.

So I've built a new version of DNS Agent that will skip the "ping" step but DNS Agent will still make sure that the server will respond to the port relevant for DNS updates before trying to issue the update.

DNS Agent 1.0.1. is available for download now.

Posted at 1:05AM UTC | permalink

Mac@Work
Put your Mac to Work

• Sivasothi.com? Now how would you do something like that?
• Weblogs. Download and start a weblog of your own.
• A Mac Business Toolbox
A survey of the possibilities
• A Business Scenario
How we could use Macs in businesses
• VPN Enabler for Mavericks
• MailServe for Mavericks
• DNS Enabler for Mavericks
• DNS Agent for Mavericks
• WebMon for Mavericks
• Luca for Mavericks
• Liya for Mountain Lion & Mavericks
• Postfix Enabler for Tiger and Panther
• Sendmail Enabler for Jaguar

Services running on this server, a Mac Mini running Mac OS X 10.9.2 Mavericks:

  • Apache 2 Web Server
  • Postfix Mail Server
  • Dovecot IMAP Server
  • Fetchmail
  • SpamBayes Spam Filter
  • Procmail
  • BIND DNS Server
  • DNS Agent
  • WebDAV Server
  • VPN Server
  • PHP-based weblog
  • MySQL database
  • PostgreSQL database

all set up using MailServe, WebMon, DNS Enabler, DNS Agent, VPN Enabler, Liya and our SQL installers, all on Mavericks.