perfSONAR User Q&A and Other Discussion

[Brian Candler <>]

On 16/02/2016 12:44, Garnizov, Ivan (RRZE) wrote:
> I believe there is something strange going on there.
> I would not expect to have a tracepath daemon listening on any port.
There is no daemon which is "listening" on this port.

perfsonar is scheduling periodic runs of tracepath. When it runs, it 
creates a socket and binds to an ephemeral port in order to send 
packets. When it has finished, it terminates.

This is just how sockets work.

>   I would not expect to have a tracepath daemon at all!
There is no tracepath daemon, only the perfsonar scheduler which 
periodically runs tracepath.

> Please share how do you come to this conclusion/inquiry: " tracepath only cares 
> about the intermediate hops and not the final destination"
perfsonar's own iptables rules do not permit tracepath packets in the 
port range I observed.

Therefore, either this is an oversight, or the perfsonar developers 
don't care about whether tracepath can reach the final hop or not.

Regards,

Brian.