[zebra 22972] IPSEC in Protocols ??

Hi all ,
     has any implementation of any protocol supported in zebra/quagga
uses/using IPsec mechanism ??

if not then

what will be beneficial, implement IPsec within protocol or
IPsec mechanism can bee integrated in zebra/quagga ??

And also what should bee considered while doing this i.e Integrate
openswan like IPsec tools witin zebra/quagga or Implement our own
IPsec mechanism ??

thanks,
ashish