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April 2010

Properly stopping a SIP flood

posted to writings on apr 11th, 2010 with tags asterisk, openbsd, ruby, security, superblock, voip, and work

At about 9am yesterday morning, I noticed on the monitor that the CPU utilization of one of my servers was abnormally high, in addition to a sustained 1mbit/sec of inbound traffic and 2mbits/sec of outbound traffic. syslog messages from Asterisk showed it to be a SIP brute force attack, so I dropped the offending IP (an Amazon EC2 instance IP) into /etc/idiots to block it and went back to my work.

A while later, I noticed the traffic still hadn't died down, so I reported the incident to Amazon and my server's network provider. No luck on either front; Amazon just sent back a form reply stating the incident was forwarded to the EC2 instance's owner (yeah, seriously) and the network provider said they wouldn't bother adding an ACL to their border equipment unless it was needed to protect their entire network. With the IP blocked on my server, the CPU utilization had died down and it was no longer sending out reply traffic, but I was worried about the inbound garbage traffic counting towards the server's monthly bandwidth cap.

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April 2008

you're not living, you're just killing time

posted to writings on apr 20th, 2008 with tags corduroy, superblock, and work

after some delays in getting a credit card processor hooked up to the signup system, corduroy is live.

Continue reading 18 words...

full tilt boogie

posted to writings on apr 9th, 2008 with tags activerecord, corduroy, quickbooks, rails, ruby, superblock, and work

"we" have been working pretty hard lately on corduroy, a web-based billing system for small businesses. the live demo site is available showing off its features and functionality and the signup system will be ready shortly to start taking subscriptions.

i started writing corduroy years ago out of a personal need for a billing system for superblock. i tried quickbooks and hated it; all i wanted was a simple system for making professional-looking invoices and keeping tabs on my accounts. so, i quickly ditched quickbooks and started writing a web-based system in ruby on rails which i have been using ever since.

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