just spent the morning playing with a little application called Nipper (http://www.titania.co.uk/nipper.php) so I thought I'd share my experiences.
From the site:
Nipper performs security audits of network device configuration files. The report produced by Nipper includes; detailed security-related issues with recommendations, a configuration report and various appendices. Nipper has a large number of configuration options which are described on this page.
The current version is 0.11.5, whilst I was initially put off by the low (0.) version number it seems to be stable and feature rich. From the changelog the project has been active for over a year and appears to be quite actively developed.
From an external testing viewpoint it isn't going to be much use as it requires a copy of the relevant devices configuration to run. However it could speed up a second stage infiltration if this can be obtained via other methods, such as SolarWinds configuration retrieval tool for cisco devices if an SNMP community with read/write privileges can be obtained. Obviously, those auditing their own networks shouldn't have this problem.
Nipper appears to be a useful tool from an auditing perspective, it investigates the device from a number of different aspects, producing a nicely written and readable report for output (HTML format by default). From the configurations I've run through it so far seem to indicate that I may spend the rest of the day researching the findings whilst completing weakness report forms and change requests
So far I've only been able to test Nipper's abilities with Cisco IOS switch and router devices. Nipper boasts abilities to function with a broad range of Cisco devices along with most major firewall manuacturers (Juniper, Checkpoint, Nortel and SonicWall). If anyone has used Nipper for other devices I would be interested to know how the functionality compares, especially as the site states "Please note that the level of support for each type of device varies."
Overall seems like I nice tool that I'm going to keep around in my bag of tricks for the time being.