From Rob Hoes in xen-api:
This is a proposal to introduce functionality in XCP to reset the networking
configuration of an XCP host to the state it would be in after a fresh install.
This is useful in case you simply want to configure networking on a host from
scratch, and helps to recover a host from a badly configured state. This also
makes it possible to recover from situations in which a pool slave cannot
contact the master anymore due to incorrect networking settings.
The complete proposal is on the wiki:
Any comments or feedback are appreciated!