[CentOS] script network reconfig after Centos 5->6 upgrade?

I need to upgrade a bunch of centos  5 servers to 6.x in the near
future, mostly keeping the same connectivity and functionality.    Are
there any tools that will examine a running 5.x box and produce the
appropriate /etc/udev/rules.d/70-persistent-net.rules (etc). to make
the same box come up with the same interface names with the same IPs
it had before?

--
  Les Mikesell
    lesmikesell at gmail.com