I have enabled Jumbo frames on 2 EC2 (M5 and R5D sizes) Windows server 2019 instances with ENA, the instances are in the same subnet and I have put them in a cluster placement group for good measure. I used the command Set-NetAdapterAdvancedProperty -Name "Ethernet" -RegistryKeyword "*JumboPacket" -RegistryValue 9015
to enable jumbo frames. I additionally also ran the command netsh interface ipv4 set subinterface "Ethernet" mtu=9001
However, when I try to ping one instance from another using the jumbo frame packet size on the public IP, using the command below, I am still seeing that packet are dropped. Security groups have the ICMP traffic enabled and ping works with regular packet sizes.
Ping xx.xx.xx.xx -f -l 9000
Packet needs to be fragmented but DF set.
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss)
Can anybody suggest what I may be missing here?