## Massive Key Re-Exchange

We are having repeated key re-exchanges for over 10 minutes with large file. It has always worked in the past but this weekend it seems to be stuck in this process of key re-exchange.

Any thoughts on what we can try? We run WinSCP via script and download the file through SSIS.

Any thoughts on what we can try? We run WinSCP via script and download the file through SSIS.

> 2021-10-11 06:17:25.828 Type: SSH_FXP_READ, Size: 37, Number: 1285 . 2021-10-11 06:17:59.284 Initiating key re-exchange (too much data received) . 2021-10-11 06:17:59.316 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:17:59.382 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:17:59.382 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:17:59.382 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:17:59.382 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:18:32.479 Initiating key re-exchange (too much data received) . 2021-10-11 06:18:32.512 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:18:32.578 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:18:32.578 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:18:32.578 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:18:32.578 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:19:06.026 Initiating key re-exchange (too much data received) . 2021-10-11 06:19:06.058 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:19:06.124 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:19:06.124 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:19:06.125 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:19:06.125 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:19:40.126 Initiating key re-exchange (too much data received) . 2021-10-11 06:19:40.160 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:19:40.224 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:19:40.224 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:19:40.224 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:19:40.224 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:20:14.900 Initiating key re-exchange (too much data received) . 2021-10-11 06:20:14.932 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:20:14.997 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:20:14.997 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:20:14.997 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:20:14.997 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:20:47.918 Initiating key re-exchange (too much data received) . 2021-10-11 06:20:47.947 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:20:48.014 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:20:48.014 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:20:48.015 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:20:48.015 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:21:24.396 Initiating key re-exchange (too much data received) . 2021-10-11 06:21:24.427 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:21:24.491 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:21:24.491 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:21:24.491 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:21:24.491 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:22:00.490 Initiating key re-exchange (too much data received) . 2021-10-11 06:22:00.519 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:22:00.584 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:22:00.584 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:22:00.584 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:22:00.584 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:22:35.913 Initiating key re-exchange (too much data received) . 2021-10-11 06:22:35.941 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:22:36.007 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:22:36.007 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:22:36.007 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:22:36.007 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:23:10.227 Initiating key re-exchange (too much data received) . 2021-10-11 06:23:10.259 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:23:10.323 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:23:10.323 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:23:10.324 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:23:10.324 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:23:45.440 Initiating key re-exchange (too much data received) . 2021-10-11 06:23:45.498 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:23:45.565 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:23:45.565 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:23:45.565 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:23:45.565 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:24:19.714 Initiating key re-exchange (too much data received) . 2021-10-11 06:24:19.745 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:24:19.809 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:24:19.809 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:24:19.809 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:24:19.810 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:24:54.102 Initiating key re-exchange (too much data received) . 2021-10-11 06:24:54.134 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:24:54.198 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:24:54.198 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:24:54.198 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:24:54.198 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:25:28.818 Initiating key re-exchange (too much data received) . 2021-10-11 06:25:28.852 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:25:28.920 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:25:28.920 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:25:28.920 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:25:28.920 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:26:03.813 Initiating key re-exchange (too much data received) . 2021-10-11 06:26:03.840 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:26:03.905 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:26:03.905 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:26:03.905 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:26:03.905 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:26:39.244 Initiating key re-exchange (too much data received) . 2021-10-11 06:26:39.275 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:26:39.339 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:26:39.339 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:26:39.340 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:26:39.340 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:27:14.363 Initiating key re-exchange (too much data received) . 2021-10-11 06:27:14.394 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:27:14.460 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:27:14.460 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:27:14.460 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:27:14.460 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:27:48.930 Initiating key re-exchange (too much data received) . 2021-10-11 06:27:48.960 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:27:49.027 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:27:49.027 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:27:49.027 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:27:49.027 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:28:24.297 Initiating key re-exchange (too much data received) . 2021-10-11 06:28:24.328 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:28:24.393 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:28:24.393 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:28:24.393 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:28:24.393 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:28:59.460 Initiating key re-exchange (too much data received) . 2021-10-11 06:28:59.492 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:28:59.556 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:28:59.556 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:28:59.557 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:28:59.557 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:29:34.320 Initiating key re-exchange (too much data received) . 2021-10-11 06:29:34.351 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:29:34.416 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:29:34.416 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:29:34.416 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:29:34.416 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:30:08.252 Initiating key re-exchange (too much data received) . 2021-10-11 06:30:08.283 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:30:08.348 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:30:08.348 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:30:08.348 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:30:08.348 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:30:42.822 Initiating key re-exchange (too much data received) . 2021-10-11 06:30:42.853 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:30:42.918 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:30:42.918 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:30:42.918 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:30:42.918 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:31:17.697 Initiating key re-exchange (too much data received) . 2021-10-11 06:31:17.736 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:31:17.801 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:31:17.801 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:31:17.802 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:31:17.802 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:31:53.303 Initiating key re-exchange (too much data received) . 2021-10-11 06:31:53.333 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:31:53.397 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:31:53.397 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:31:53.397 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:31:53.397 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:32:28.118 Initiating key re-exchange (too much data received) . 2021-10-11 06:32:28.148 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:32:28.212 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:32:28.213 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:32:28.213 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:32:28.213 Initialised HMAC-SHA-256 inbound MAC algorithm . 2021-10-11 06:33:03.496 Initiating key re-exchange (too much data received) . 2021-10-11 06:33:03.529 Doing ECDH key exchange with curve nistp256 and hash SHA-256 . 2021-10-11 06:33:03.593 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption . 2021-10-11 06:33:03.593 Initialised HMAC-SHA-256 outbound MAC algorithm . 2021-10-11 06:33:03.593 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption . 2021-10-11 06:33:03.593 Initialised HMAC-SHA-256 inbound MAC algorithm