Jon Parise's Blog

October 26, 2009

I often use Password Composer (written by Johannes la Poutré) to generate
unique, per-site passwords. It does an excellent job because it's simple,
unobtrusive, and reliable. The one downside is that you need to have it
available in order to (re)generate the password for a given web site, and that
isn't always convenient, despite the large number of existing Password
Composer implementations.

The main place I find myself missing Password Composer is on my iPhone. Theonly current solution...

0 comments Published on October 26, 2009 00:02 | 6 views

August 25, 2009

Bonjour (formerly Rendezvous) is Apple's service discovery protocol. It
operates over local networks via multicast DNS. Server processes announce
their availability by broadcasting service records and their associated ports.
Clients browse the network in search of specific service types, potentially
connecting to the service on the advertised port using the appropriate network
protocol for that service.

A common example of Bonjour in action is iTunes' music library sharingfeature. iTunes shari

0 comments Published on August 25, 2009 10:03 | 4 views

Classless in-addr.arpa. delegation allows network administrators to provide
authoritative reverse DNS on subnets that don't fall on octet boundaries.
This is especially useful for subnets comprised of less than eight bits in the
host portion of the address (i.e. smaller than a class C).

There are two important things to remember: first, we're dealing withclassless subnets, meaning they don't align themselves neatly with IPv4'soctet boundaries (like a class A, B, C, D, or E network); and second, o

0 comments Published on August 25, 2009 10:03 | 1 view

This paper discusses the implementation of virtual Ethernet tunnels using
OpenBSD. The current release of OpenBSD at the time of writing (2001) was
version 2.9, so some of the material may be fairly dated. I haven't revisited
the details since then.

Overview

Without going too deep into the technical details, a virtual Ethernet tunnel
uses packet encapsulation, Ethernet bridging, and IPSec encryption to
tunnel a subnet from one host to another host over a public network
(generally, the Internet).

0 comments Published on August 25, 2009 10:03 | 1 view

The Vim text editor supports highly-configurable color schemes which build
upon the editor's rich syntax highlighting system. The stock Vim distribution
includes a number of color schemes, and many more are available from the Vim
Scripts repository
.

Color scheme definitions are simply normal Vim scripts that live in the
colors/ directory of the Vim runtime hierarchy (see :help runtimepath).

Color schemes are loaded using the :colorscheme command. The scheme'sname is determined by the filename of

0 comments Published on August 25, 2009 10:03 | 1 view

Being able to reload code modules is one of the many nice features of Python.
This allows developers to modify parts of a Python application while the
interpreter is running. In general, all that needs to be done is pass a
module object to the imp.reload() function (or just reload() in Python
2.x), and the module will be reloaded from its source file.

There are a few potential complications, however.

If any other code references symbols exported by the reloaded module, they maystill be bound to t

0 comments Published on August 25, 2009 10:03 | 3 views

August 15, 2009

Being able to reload code modules is one of the many nice features of Python.
This allows developers to modify parts of a Python application while the
interpreter is running. In general, all that needs to be done is pass a
module object to the imp.reload() function (or just reload() in Python
2.x), and the module will be reloaded from its source file.

There are a few potential complications, however.

If any other code references symbols exported by the reloaded module, they maystill be bound to t

0 comments Published on August 15, 2009 18:02 | 1 view

May 28, 2009

Bonjour (formerly Rendezvous) is Apple’s service discovery protocol. It
operates over local networks via multicast DNS. Server processes announce
their availability by broadcasting service records and their associated ports.
Clients browse the network in search of specific service types, potentially
connecting to the service on the advertised port using the appropriate network
protocol for that service.

A common example of Bonjour in action is iTunes’ music library sharingfeature. iTunes shari

0 comments Published on May 28, 2009 22:56 | 1 view

Classless in-addr.arpa. delegation allows network administrators to provide
authoritative reverse DNS on subnets that don’t fall on octet boundaries.
This is especially useful for subnets comprised of less than eight bits in the
host portion of the address (i.e. smaller than a class C).

There are two important things to remember: first, we’re dealing withclassless subnets, meaning they don’t align themselves neatly with IPv4’soctet boundaries (like a class A, B, C, D, or E network); and second, o

0 comments Published on May 28, 2009 22:56 | 1 view

This paper discusses the implementation of virtual Ethernet tunnels using
OpenBSD. The current release of OpenBSD at the time of writing (2001) was
version 2.9, so some of the material may be fairly dated. I haven’t revisited
the details since then.

Overview

Without going too deep into the technical details, a virtual Ethernet tunnel
uses packet encapsulation, Ethernet bridging, and IPSec encryption to
tunnel a subnet from one host to another host over a public network
(generally, the Internet).

0 comments Published on May 28, 2009 22:56 | 1 view