Strange and undocumented (?) result in traceroute JSON output
Measurement #1013405 contains: "result": [ { "x": "*" }, { "late": 20, "ttl": 61, "from": "88.79.15.141", "size": 96 }, { "x": "*" }, { "x": "*" } While "late" is documented <https://atlas.ripe.net/doc/data_struct#v4400_traceroute>, the lack of "rtt" field is not and crashes tools like json2traceroute.py.
Hi Stephane, On 2013/07/17 9:17 , Stephane Bortzmeyer wrote:
Measurement #1013405 contains:
"result": [ { "x": "*" }, { "late": 20, "ttl": 61, "from": "88.79.15.141", "size": 96 }, { "x": "*" }, { "x": "*" }
While "late" is documented <https://atlas.ripe.net/doc/data_struct#v4400_traceroute>, the lack of "rtt" field is not and crashes tools like json2traceroute.py.
I'll update the documentation to say that rtt won't be there for packets that are late. Philip
On 7/17/13 9:17 AM, Stephane Bortzmeyer wrote:
Measurement #1013405 contains:
"result": [ { "x": "*" }, { "late": 20, "ttl": 61, "from": "88.79.15.141", "size": 96 }, { "x": "*" }, { "x": "*" }
While "late" is documented <https://atlas.ripe.net/doc/data_struct#v4400_traceroute>, the lack of "rtt" field is not and crashes tools like json2traceroute.py. tools like json2traceroute.py which aim to reconstruct the routing vector should be aware of responses which arrive out of order; packets which are 'late' or show 'ittl' in the result require special attention because the 'from' address listed verly likely is from a router at a different hop.
json2traceroute.py could simply ignore the 'strange' results by changing the lines ... else: rtt.append(hr["rtt"]) hopfrom = hr["from"] ... to ... elif (not "late" in hr) and (not "ittl" in hr): rtt.append(hr["rtt"]) hopfrom = hr["from"] ... -- Rene
participants (3)
-
Philip Homburg -
Rene Wilhelm -
Stephane Bortzmeyer