Anticipate their emergency procedures, and ship them a binder wrapped with dire warnings should it be removed from the data center. Multiple customers have said this has saved their bacon.
Emergency procedures for administrating the network gear. There's two sections: 1) symptom->fix procedures, and 2) how to rebuild everything in the network from scratch in case it got wiped.
The reason it's in hardcopy is because you can't look stuff up on the Internet if the Internet is down.
