On 11/6/2010 4:40 PM, sthaug@nethelp.no wrote:
For some value of "works". There are way too many places filtering ICMP for PMTUD to work consistently. PMTUD is *not* the solution, unfortunately.
He was referring to the updated RFC 4821. " In the absence of ICMP messages, the proper MTU is determined by starting with small packets and probing with successively larger packets. The bulk of the algorithm is implemented above IP, in the transport layer (e.g., TCP) or other "Packetization Protocol" that is responsible for determining packet boundaries." It is designed to support working without ICMP. It's draw back is the ramp time, which makes it useless for small transactions, but it can be argued that small transactions don't need larger MTUs. Jack