Following up on yesterday's diary on an increase in Protocol 47 traffic.   Thanks to everyone who sent the ISC PCAPs and more information.

Current speculation is the Protocol 47 uptick is backscatter from a DDOS containing GRE traffic and using random source IPs.  

While all of the packets appear to be IPv4 packets encapsulated in GRE, there are two flavors of packets involved.  The smaller packets are consistently 66 bytes long and contain no data.

The larger packets vary in size, but are typically in the high 500's of bytes and contain 512 bytes of data.  The data appears to be random.

While the sources show IPs from over 50 countries, about 55% of the source IPs in my data were from Taiwan, presumably these IPs are the primary attack targets.  

Top 10 Sources by Country

The majority of those were from IPs associated with Chungwa Telecom (HINET-NET), the largest ISP/Carrier in Taiwan.

Top 20 Sources by IP

-- Rick Wanner MSISE - rwanner at isc dot sans dot edu - http://namedeplume.blogspot.com/ - Twitter:namedeplume (Protected)