Tag Archives: tech blog

Tomato Firmware: Increased Transmit Power Does More Harm Than Good?

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I had turned the routers up to 80 mW and the problem was still occurring. Upon some research I found that as the Transmit power levels of the routers increased, so did the radio noise produced by the routers. I decided to turn the routers back down, to a level lower than when I first began to administer the network. After this change, users noticed an immediate improvement in the quality of their wireless connections. Everything was (and still is) running stable. The users are no longer losing Internet connection and are maintaining proper network speeds.

via Tomato Firmware: Increased Transmit Power Does More Harm Than Good? | Techerator.

I’m seeing the same thing with the Tomato firmware.  The firmware is nicer than Linksys but I thought increasing the power of this router would increase the range but I suppose it’s more complicated than that.

Loopholes in Verified by Visa & SecureCode

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At issue is a security protocol called “3 Domain Secure,” (3DS), a program designed to reduce card fraud and shift liability for fraud from online merchants to the card issuing banks. Visa introduced the program in 2001, branding it “Verified by Visa,” and MasterCard has a similar program in place called “SecureCode.”

Cardholders who chose to participate in the programs can register their card by entering the card number, filling in their ZIP code and birth date, and picking a passcode. When cardholders go to use that card at a merchant site that uses 3DS, the shopper then enters the code, which verified by the issuing bank and is never shared with the merchant site.

via Loopholes in Verified by Visa & SecureCode — Krebs on Security.

Why Hypercard Had to Die

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The reason for this is that HyperCard is an echo of a different world. One where the distinction between the “use” and “programming” of a computer has been weakened and awaits near-total erasure. A world where the personal computer is a mind-amplifier, and not merely an expensive video telephone. A world in which Apple’s walled garden aesthetic has no place.

What you may not know is that Steve Jobs killed far greater things than HyperCard. He was almost certainly behind the death of SK8. And the Lisp Machine version of the Newton. And we may never learn what else. And Mr. Jobs had a perfectly logical reason to prune the Apple tree thus. He returned the company to its original vision: the personal computer as a consumer appliance, a black box enforcing a very traditional relationship between the vendor and the purchaser.

via Loper OS » Why Hypercard Had to Die.

nf_conntrack and the conntrack program

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Anyway I did at a fast cat /proc/net/nf_conntrack | grep 5060 to get all connection tracking entries for SIP. And I found more than one, here is on example.

via nf_conntrack and the conntrack program | Robert Penz Blog.

More info on conntrack here…

The timeout for this entry is 180 sec and 172 seconds to go, and the SIP client was all the time sending new probes and therefore the connection was never dropped. What can you do in this instance? You can install conntrack. It is a userspace command line program targeted at system administrators. It enables you to view and manage the in-kernel connection tracking state table. If you want to take a look at the manual without installing it (apt-get install conntrack) you can take a look at this webpage which contains the man page. With this program I did delete the entries with the wrong IP address and everything worked again.

Building an XMPP Server – Part 1

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After reading several reviews, I chose ejabberd. Ejabberd can be downloaded from the previous link, but it also has the advantage of being located in the Ubuntu repositories. I created a Ubuntu Server and loaded ejabberd using “sudo apt-get install ejabberd”. Couldn’t be easier! And using a virtual machine to build the server means I can install it at customer locations without building a new server every single time, it will just need to be reconfigured once it is spun up.

via Building an XMPP Server – Part 1 | Jameson Networks Blog.

Ejabberd is also part of the fedora repositories but not part of the CentOS repos.