Path MTU Discovery and Fragmentation Issues
Translator participates in Path MTU discovery
adjusts Path MTU to account for header size differences
Mismatch in specified IPv6 & IPv4 minimum MTU
IPv6 uses 1280 bytes and IPv4 uses 576 bytes minimum Path MTU
translator fragments IPv6 min MTU packets into IPv4 min MTU packets
Many IPv4 implementations do not use Path MTU discovery
must carry fragmentation info end-to-end to ensure proper reassembly
must set the Don’t Fragment bit to false if packet is translated back to IPv4