As this is sysctl settable and readable directly, I hope it's not 
something thats too rough to integrate... I'd like an option to disable 
the sending and accepting of ICMP redirects, say via check box, within 
Advanced Settings.

Relevant sysctls:
net.inet.ip.redirect
   1 - sending redirects is enabled
   0 - sending redirects is disabled

net.inet.icmp.drop_redirect
   1 - ignore incoming icmp redirects
   0 - allow icmp redirects to be processed

Joshua Coombs