[c-nsp] 12.2SXH 'archive' / Configuration Management

[Alex Howells]

Aloha :)

What is the collective opinion on the best way to do change monitoring / 
management with router and switch configurations?

    http://www.cymru.com/Documents/secure-ios-template.html

That template makes fairly extensive use of the 'archive' command but 
some older IOS doesn't include that functionality; I've also seen/heard 
RANCID being deployed and would like something which "Just works".

We're a small ISP in the United Kingdom who're just transitioning from 
having one network engineer to a few people being involved - it 
therefore seems worthwhile to try and track changes for later fault 
diagnosis if someone is off on holiday, and for security/sanity reasons. 
  Ideally it'd be able to cope with most/all of the follow devices:

     18xx and 28xx ISRs
     26xx (Console Servers)
     7600s (Core / Edge)
     2950/2960 Switches
     3550/3560 Switches
     837/857/877 ADSL (Home Equipment)
     ..random other stuff.. (Network Lab)

Real-world battle stories appreciated, custom hacks also considered ;) 
Something capable of stripping out sensitive information like passwords 
from the downloaded configurations would be nice, integration with a 
half-decent system like Subversion too... Perhaps something which pulls 
the configuration(s) via SNMP - is that going to be easy to secure? 
Definitely something which doesn't put undue load on the 
routers/switches as we've got some older kit deployed :)

What's the collective opinion on how often you should poll devices? 
Obviously if not often enough you lose granularity for lots of small 
changes being implemented, if too often, things go boom?

Thanks, as always,
Alex