RPC request sent to 127.0.0.1 becomes from other IP on machine

Hi,

Mark has reported a problem via email where the nfsuserd daemon sees
requests coming from an IP# assigned to the machine instead of 127.0.0.1.
Here's a snippet from his message:
  Ok, I have Plex in a jail and when I scan the remote NFS file share the
  *local* server's nfsuserd spams the logs.
Spamming the logs refers to the messages nfsuserd generates when it gets
a request from an address other than 127.0.0.1.

I think the best solution is to switch nfsuserd over to using an AF_LOCAL
socket like the gssd uses, but that will take a little coding and probably
won't be MFCable.

I've sent him the attached patch to try as a workaround.

Does anyone happen to know under what circumstances the address 127.0.0.1
gets replaced?

And do you know if it will always be replaced with the same
address?
(I'm basically wondering if the workaround needs to be a list of IP addresses
 instead of a single address?)

Thanks in advance for any help with this, rick