Something like Chef or Puppet could, in theory, be used at the network level. The problem with those two applications specifically is that they expect to run a client on the machines they configure, something that's not possible with most network gear. But you certainly could build something like Chef or Puppet that runs centrally and connects out with Telnet or SSH to the each piece of network gear to configure them.
There are some commercial systems (like CiscoWorks) that are kind of like this, but all the useful functionality is bogged down in enterprisy crappyness. :-(
There are some commercial systems (like CiscoWorks) that are kind of like this, but all the useful functionality is bogged down in enterprisy crappyness. :-(