Say I have Host1 & 2 connected to a router with different speeds.
Host1 <--100 Mbps--> Router <--10 Mbps--> Host2
Host1 sends 10MB of UDP data using nc command to Host2, but the Host2 fails in reassembling fragmented packets and sends ICMP(Time-to-live exceeded/Fragment reassembly time excedded).
When the both ends are 100 Mbps, I don't see any failure and no fragmentation happens.
I tried to avoid fragmentation by following methods
1. Enabling PMTU on destination, router
echo 0 > /proc/sys/net/ipv4/ip_no_pmtu_disc
2. Reducing MTU to 576 from 1500
But still fragmentation happens. I can see through wireshark log. Can you please guide me to avoid fragmentation and how to handle this scenario.
Edit:
This is kind of stress scenario from router perspective. I should not change anything on source/destination side.