Hi, All There's a set up that involves AP300 adopted to RFS6000 (WiNG 4.2.0.0-024R) over GRE tunnel. GRE tunnel causes packets to be fragmented and does not defragment them on the other end. Tested: When you send a ping from RFS to AP (with size 1600) it returns to RFS as 2 fragmented packets. But RFS fails to defragment them (says ping timed out)! Obviously, this causes issues with transmitting client data: since L3 tunnel runs over UDP there's no way to use PMTUD / MSS Clamping - the packets get fragmented (and not defragmented by RFS) again. Firewall is disabled, logs don't show any fragmentation attack or anything like that. Why does RFS not defragment own packets?