IP fast forwarding and setkey

[Paul S.]

Hi folks,

I plan to make an edge router out of a freebsd system with OpenBGPD + 
FreeBSD 10, or such.

I've been reading up, and noticed that the net.inet.ip.fastforwarding 
flag provides rather nice performance benefits.

My issue is, my upstream networks insist on using TCP MD5 authentication 
on their BGP sessions.

This is fine, except on FreeBSD -- I'm going to have to use the setkey 
utility to set those since native PF_KEY support for OpenBGPD does not 
seem available.

Now, since setkey is part of IPSec, and there are countless warnings 
about using IPSec and fastforwarding together in the manpage, am I 
correct in assuming that this will not work if I have fastforwarding 
enabled?

Is there any way to make it work? Quagga, from what I've read, seems to 
also be in the same boat (Usage of setkey required for TCP MD5).

I tried searching the manpages, but couldn't locate anything concrete on 
this.

Any assistance/replies are welcome.

Thank you!