Dean Anderson; >>I recommend that, to avoid long initial delay and intermediate >>lack of communication after path changes of, PMTUD should turnd >>off by default and should be activated only on extreme >>conditions. > Just the opposite, unless you want to lose connectivity with a number of > web servers that want to send big packets with DF turned on. There were (still are?) number of web servers that wanted to send big packets with DF turned on, because PMTUD was turned on on the servers but ICMP errors were filtered. > A number of commercial > products and applications do rely on PMTU to work, and will do an PATH MTU > discovery, and send the MTU sized packets with DF (don't frag). and send packets larger than MTU expecting to receive ICMP errors in vain. Read the original mail of the thread on the reality. > This is the first I have heard that path mtu discovery software was > unreliable. PMTUD software is unreliable!? Then, it is anther reason to avoid it. Can you tell me who said it with an appropriate reference? Masataka Ohta _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf