Auteur Sujet: J'ai une question à propos de la fonction " iperf3 --cport "  (Lu 1102 fois)

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Byounguk Lee

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Hello!

Thank you for your previous replies.
It really helped me.

I have a question about "--cport". I use this function by typing command like 'iperf3 -c 192.0.0.120 -p 12000 -u -B 192.0.0.110 --cport 11000'.
This command means that client use ip & port, 192.0.0.110 and 11000.

But I have checked packet in detail by using tcpdump,
It show that first packet from 192.0.0.110 client do not have port 11000, but randomly generated port.
After connection is accomplished, I think, 192.0.0.110 client generate packet having 11000.

Is it intended? I think that It is unnatural for client to use randomly port first, despite of specify port by using '--cport'.


toujours remercier!

-Byoung Uk Lee

Byounguk Lee

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J'ai une question à propos de la fonction " iperf3 --cport "
« Réponse #1 le: 23 mai 2016 à 13:02:06 »
and I found by using wire-shark that when I use '-u --cport',it means packet is udp, and have specific port number', udp packet generated by iperf3 do not have specified port by command. In tcp case, '--cport' command work well.

kgersen

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J'ai une question à propos de la fonction " iperf3 --cport "
« Réponse #2 le: 23 mai 2016 à 15:53:43 »

Is it intended? I think that It is unnatural for client to use randomly port first, despite of specify port by using '--cport'.


AFAIK yes it's intended. Iperf3 client & server 1st establish a tcp 'control' connection between them and then perform the 'data transfer(s)' (called "stream(s)". (s) because there can be more than one at the same time). The --cport only apply to the stream(s).