Yeah, and then when they went to a road course, the whole thing fell apart since they could only turn left.

A firm I worked with recently tore down an arbitrage network (they were getting out of the business as it was not core) which comprised of a great deal of Layer 2 dark fiber between sites in NYC and an external data center in NJ, Force 10 fabric switches with multiple paths to server clusters, and a great many Sun X-series servers running Linux. This arbitrage network bypassed the standard corporate (i.e. Cisco-based) network as they wanted exclusivity, higher bandwidth and as much speed as possible. Still, there were issues and the whole environment was scrapped since the actual returns did not match the expectations or cover the costs.

When I looked over the shoulders of the designers (they didn't want too much support from the regular network engineering team) they were concerned with raw performance and not as much with security or other daily operational issues. I would characterize it as the difference between, say, a NASCAR Sprint Cup car and your regular transportation. The former is purpose-built solely for performance while the other has to contend with safety requirements, daily functionality, and a lower common denominator for use.

Besides echoing earlier comments about keeping in touch with colleagues from previous employers, one feature of Linked In I find helpful is with research for jobs and companies. A head hunter pinged me about an interesting-sounding position at a local university. I went to the school's website and did not find it in their listings. I saw that one of my former colleagues was at a similar level at that school, so I queried him about the position. His reply was that there was no such position open - and he confirmed it with the VP supposedly hiring for that job. So, having the Linked In connections provides a great deal of added support to winnow out the garbage from recruitment firms.

True story - I start my new job as Network Team Lead with one cabling tech and one temporary consultant hired to fill in after the rest of the network team resigned. My documentation? Six large moving boxes full of c**p from the previous two leads and their managers. No online docu, no drawings, and a whole lot of head-scratching. This lead to us scrapping a major disaster recovery test because it was based on a network that had been dismantled two years prior, and no one had bothered to maintain the documentation. Yes, the company was in bad shape, but it was improving. By the time I left four years later (after a merger with a larger firm who did not require my services) we knew down to the specific patch cable where things were, and what processes we needed for hardware/software configuration.

Write it down!