workload myths: prevalence of IP fragmentation

myth: there is no fragmented traffic
data:  while true that only a small percentage (0.09% - 1.6%) of traffic is fragmented, this number is growing.  Some protocols, for example IGMP, have fragmented traffic far exceeding non-fragmented traffic.

myth: fragmented traffic exists only on LANs
data:  we've monitored aggregated exchange points and backbone links.

tcp traffic is never fragmented
data:  while tcp traffic is fragmented much less frequently than other protocols due to path MTU discovery, we monitored 0.009% by packets (0.019% by bytes) of fragmented tcp traffic. and a majority of fragmented tunneled traffic is TCP!

NFS causes all (or almost all) fragmented traffic
data:  tunneled traffic (IPENCAP, IPIP, GRE, UDP L2TP), ICMP, and RealMedia all cause more fragmented traffic than NFS (0.1%).