DoS, ICMP, proxies, SYNDefender

From: Tim Bass <bass@linux.silkroad.com>

I feel like a cheerleader 'Give me an U N R E A C H A B L E'
wha-at-ya-got .........

   Tim, unfortunately ICMP UNREACHABLE can be sent some intermediate
router during routing flip process. For this reason some customer
prefer cut off this sort of ICMP - it would break running TCP connection.

          - Leonid Yegoshin, LY22