Great to see an Infrastructure forum at last – long overdue, this seems to be a widely forgotten area yet so crucial.
In retrospective network qualification do I need to actually test all cables?
No you don’t – you could typically eliminate patch leads between servers and switches as long as you buy good ones and are within your conformance standards or specification. All horizontal cables must be tested between patch panels and wall outlets (both copper and fibre) – you need to know they’re reliable and not exceeding any requirements such as 100m for copper.