NAME

       paris-traceroute  -  An advanced implementation of traceroute which correctly handles load
       balancing servers among other things

DESCRIPTION

       We introduce Paris traceroute, a new traceroute to respond to load balancing routers.  Its
       key  innovation  is  to control the probe packet header fields in a manner that allows all
       probes towards a destination to follow the same path in  the  presence  of  per-flow  load
       balancing.  It  also  allows  a  user to distinguish between the presence of per-flow load
       balancing and per-packet load balancing. Unfortunately, due to the random nature  of  per-
       packet  load  balancing,  Paris  traceroute  cannot  perfectly  enumerate all paths in all
       situations. But it can do considerably better than the classic traceroute, and it can flag
       those  instances  where  there  are doubts. The problem, if one wishes to maintain certain
       header fields constant, is that traceroute still  needs  to  be  able  to  match  response
       packets to their corresponding probe packets.

       Paris  traceroute  does this by varying header fields that are within the first 28 octets,
       but are not used for load balancing. In the case of TCP probes,  Paris  traceroute  varies
       the  sequence  number. In UDP probes, it is the checksum field. This requires manipulating
       the payload to yield the desired checksum, as  packets  with  an  incorrect  checksum  are
       liable to be discarded. In ICMP probes, it is a combination of the ICMP identifier and the
       sequence number. We carefully set the value of the ICMP identifier and sequence number  to
       keep  constant the header checksum of all probes to a destination. Figure 2 summarizes the
       IP, UDP, and ICMP header fields that are used by load balancers, classic  traceroute,  and
       Paris  traceroute.  We  include the ICMP type field as used for load balancing, even if we
       cannot verify it experimentally (routers only repond to one type of probes, which  is  the
       ICMP  echo  request).  Our  experiments  with  UDP,  TCP,  and IPSec probes do give strong
       evidence that routers blindly use the first four octets after the IP header combined  with
       the IP fields to do load balancing.

OPTIONS

              -h, --help                                   Displays help and usage information

              -a<ALGORITHM>, --algorithm=<ALGORITHM>       Choose which algorithm to use. Default
              is "mda".

BUGS

       No known bugs. If any are found please feel free to email us.

AUTHOR

       Julian Cromarty (julian.cromarty@gmail.com)