UDP IP Fragmentation and MTU

Question

I\'m trying to understand some behavior I\'m seeing in the context of sending UDP packets.

I have two little Java programs: one that transmits UDP packets, and the other

Answer 1

I found the following which may be of interest:

• Determine the maximum size of a UDP datagram packet on Linux
• Set the DF bit in the IP header and send continually larger packets to determine at what point a packet is fragmented as per Path MTU Discovery. Packet fragmentation should then result in a ICMP type 3 packet with code 4 indicating that the packet was too large to be sent without being fragmented.

Dan's answer is useful but note that after headers you're really limited to 65507 bytes.