I am trying to run ssh to a server continuously and quickly. Out of about 10-12 times of good run or result, once the client gets stuck. It does not connect. This we are observing after upgrading both the server and client to OpenSSL 9.6p1. We are running this cmd on the client side: ssh -vvv -p 1022 -o UserKnownHostsFile=/dev/null -o GSSAPIAuthentication=no -o StrictHostKeyChecking=no -o ConnectTimeout=60 -o PubkeyAuthentication=yes -o PreferredAuthentications=publickey -o ServerAliveInterval=60 -i /root/id_rsa root at 10.0.0.2 "/usr/sbin/dmidecode -s system-product-name" On the client side (working): debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 47: Applying options for * debug2: resolve_canonicalize: hostname 10.0.0.6 is address debug1: Authenticator provider $SSH_SK_PROVIDER did not resolve; disabling debug3: channel_clear_timeouts: clearing debug3: ssh_connect_direct: entering debug1: Connecting to 10.0.0.6 [10.0.0.6] port 1022. debug3: set_sock_tos: set socket 3 IP_TOS 0x48 debug2: fd 3 setting O_NONBLOCK debug1: fd 3 clearing O_NONBLOCK debug1: Connection established. debug3: timeout: 60000 ms remain after connect Client side non0-working: debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 47: Applying options for * debug2: resolve_canonicalize: hostname 10.0.0.6 is address debug1: Authenticator provider $SSH_SK_PROVIDER did not resolve; disabling debug3: channel_clear_timeouts: clearing debug3: ssh_connect_direct: entering debug1: Connecting to 10.0.0.6 [10.0.0.6] port 1022. debug3: set_sock_tos: set socket 3 IP_TOS 0x48 debug2: fd 3 setting O_NONBLOCK <----------- hangs here debug1: connect to address 10.0.0.6 port 1022: Connection timed out ssh: connect to host 10.0.0.6 port 1022: Connection timed out Netstat output shows client is stuck after receiving the syn-ack. It remains in SYN_RECV status. //client root at node2:~# netstat -ant | grep 1022 tcp 0 0 10.0.0.6:1022 10.0.0.5:52836 SYN_RECV //server root at node1:~# netstat -ant | grep 1022 tcp 0 0 10.0.0.5:1022 0.0.0.0:* LISTEN tcp 0 0 10.0.0.5:39668 10.0.0.6:1022 TIME_WAIT tcp 0 1 10.0.0.5:52836 10.0.0.6:1022 SYN_SENT