On Thu, 9 Apr 2020 at 01:34, Cyril Servant <cyril.servant@xxxxxxxxx> wrote: [...] > Each of our front > nodes has an outgoing bandwidth limit (let's say 1Gb/s each, generally more > limited by the CPU than by the network bandwidth), You might also want to experiment with the Ciphers and MACs since these can make a significant difference in CPU utilization and, if that's the bottleneck, your throughput. Which one is best will vary depending on your hardware, but it's likely to be either AES GCM if the hardware has AES instructions or chacha20-poly1305 if not. In the first example below the bottleneck is the source's relatively elderly 2.66GHz Intel CPU. In the second it's the gigabit network between them. $ scp -c aes256-ctr -o macs=hmac-sha2-512 ubuntu-18.10-desktop-amd64.iso.bz2 nuc:/tmp/ ubuntu-18.10-desktop-amd64.iso.bz2 100% 1899MB 63.5MB/s 00:29 $ scp -c chacha20-poly1305@xxxxxxxxxxx ubuntu-18.10-desktop-amd64.iso.bz2 nuc:/tmp/ ubuntu-18.10-desktop-amd64.iso.bz2 100% 1899MB 112.1MB/s 00:16 -- Darren Tucker (dtucker at dtucker.net) GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860 37F4 9357 ECEF 11EA A6FA (new) Good judgement comes with experience. Unfortunately, the experience usually comes from bad judgement. _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev