C:\Users\David Johnson>ping google.com -f -l 1475
Pinging google.com [66.185.95.25] with 1475 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Ping statistics for 66.185.95.25:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
C:\Users\David Johnson>ping google.com -f -l 1473
Pinging google.com [66.185.95.25] with 1473 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Ping statistics for 66.185.95.25:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
C:\Users\David Johnson>ping google.com -f -l 1472
Pinging google.com [66.185.95.25] with 1472 bytes of data:
Reply from 66.185.95.25: bytes=1472 time=17ms TTL=58
Reply from 66.185.95.25: bytes=1472 time=13ms TTL=58
Reply from 66.185.95.25: bytes=1472 time=17ms TTL=58
Reply from 66.185.95.25: bytes=1472 time=13ms TTL=58
Ping statistics for 66.185.95.25:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 13ms, Maximum = 17ms, Average = 15ms
By trial and error I see that the optimum mtu is 1472C:\WINDOWS\system32>netsh interface ipv4 show subinterfaces
MTU MediaSenseState Bytes In Bytes Out Interface
------ --------------- --------- --------- -------------
1500 1 7678156698 10595591033 Ethernet 2
4294967295 1 4065 114312 Loopback Pseudo-Interface 1
1500 1 0 198527 VMware Network Adapter VMnet1
1500 1 0 200471 VMware Network Adapter VMnet8
To set the mtuC:\WINDOWS\system32>netsh interface ipv4 set subinterface "Ethernet 2" mtu=1472
store=persistent
Ok.