On 5/30/20 5:46 AM, Anand Buddhdev wrote:
On 30/05/2020 12:32, hw@gc-24.de wrote:
Hi hw,
I'm looking for a good way to create a constant data stream that will occupy a bandwidth of about 2--5Mbit/sec between two remote hosts over the internet. I have full access to the hosts involved.
My first attempt to use scp to copy data from /dev/null on host A to /dev/null on host B, but scp says '/dev/null: not a regular file'. If something like that would work, I would be able to limit the bandwidth of this transfer in the router(s) involved so that it won't occupy all the bandwidth.
You can't read from /dev/null. You get nothing from it. You're better off using /dev/random, for example. That will give you a continuous stream of random bytes.
I would recommend to read from /dev/zero instead, it will give you a stream of zeroes. Using /dev/random is OK, but has one disadvantage in the OP case: you exhaust machine's accumulated entropy which may be more needed for other tasks (like ssh or ssl connections)...
Just my 2 cents.
Valeri
However, that's not the focus of this. You want a sustain a stream of packets between two hosts. You're better off using UDP for this. And a good tool for generating such packets would be "iperf". It can measure bandwidth between two nodes more accurately.
Regards, Anand _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos