General
1.Disable/Enable feature ssh to clear stale sessions.
2.Enable telnet as temporary access to the device. [optional]
Symptom
n9k# show processes cpu sort | egrep -i ssh
745 60 119 509 0.00% dcos_sshd
925 65 132 497 0.00% dcos_sshd
1159 63 140 453 0.00% dcos_sshd
1334 63 129 495 0.00% dcos_sshd
1490 61 118 521 0.00% dcos_sshd
1559 61 118 524 0.00% dcos_sshd
1723 62 132 473 0.00% dcos_sshd
2182 67 126 535 0.00% dcos_sshd
2869 61 121 510 0.00% dcos_sshd
3224 63 121 521 0.00% dcos_sshd
3333 62 132 473 0.00% dcos_sshd
3685 91 115 796 0.00% dcos_sshd
3749 64 140 457 0.00% dcos_sshd
3958 61 119 512 0.00% dcos_sshd
4377 68 283 242 0.00% dcos_sshd
4498 62 118 529 0.00% dcos_sshd
4699 64 137 469 0.00% dcos_sshd
4743 61 123 502 0.00% dcos_sshd
5376 62 115 539 0.00% dcos_sshd
5509 80 459 175 0.00% dcos_sshd
Conditions
Stale ssh sessions on N9K are using VTY lines and once all VTY lines are used ,clients would not be able to establish SSH session with the server.
Workaround
1.Disable/Enable feature ssh to clear stale sessions.
2.Enable telnet as temporary access to the device. [optional]
Further Problem Description
Stale ssh sessions will keep piling up even after the workaround.
New SSH sessions would not be established when vty lines are full.
