Archive for February, 2005

Viewing TCP connection data

The netstat utility provides a command line interface to retrieve system routing tables, connection states, and network statistics. Two of the available statisticss, “tcpPassiveOpens” and “tcpActiveOpens,” provide data on the number of new connections to a server (tcpPassiveOpens), and the number of connections initiated by the server (tcpActiveOpens). Both statistics counters can be retrieved with […]

Regression testing Sun and Fujitsu hardware

When I get deploy new Fujitsu and Sun hardware, I always run VTS (Validation Test Suite) on the hardware platforma. VTS performs rigorous hardware testing, and **usually** finds faults in components that are faulty out of the box. The VTS commands are available in “/opt/SUNWvts/bin.” The VTS tools rely on the RPC framework ( *grumble* […]

Apache Name-based virtual hosts

Name-based virtual hosts allow a web server to host multiple domain names (,, from one IP address. This allows a web hosting infrastructure to conserve IP address space, and simplify namespace management. Apache name-based virtual hosts are configured with the “NameVirtualHost” and “VirtualHost” directives, and rely on the HTTP “Host:” header attribute. This […]

Converting Solaris packages

The Solaris package commands (e.g., pkgproto, pkgadd, pkgtrans ) operate on two package formats. The first format is the “datastream” format. Packages created as datastream formatted packages use a single self contained file. This file includes the binary contents, application configuration files, and metadata to describe the package and installation process. The second format is […]

Grabbing a protected webpage from the command line

Ever needed to grab a password protected page from the command line? This can be accomplished with curl’s “-u” option: $ curl -k -i -u me:somethingstrong |more The username and password can be passed as an argument to the “-u” option. If you are paranoid about your password being visible on the command line, […]

Reading OpenBSD PF log entries in realtime

When the OpenBSD packet filter (PF) is configured to log traffic, each packet is logged to the OpenBSD “pflog” pseudo-device. This device can be queried with several tools, including tcpdump: oscar# tcpdump -i pflog0 -ttt -e -o tcpdump: WARNING: pflog0: no IPv4 address assigned tcpdump: listening on pflog0 Jan 23 21:27:33.361173 rule 4/0(match): block in […]

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