8 years later, we saw this on one of our customer's systems. Looking at the status of this entry, it looks like it's still unresolved?
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/483928 Title: ssh-keyscan(1) exits prematurely on some non-fatal errors Status in portable OpenSSH: Confirmed Status in openssh package in Ubuntu: Confirmed Bug description: Binary package hint: openssh-client This concerns openssh-client 1:5.1p1-5ubuntu1 in Karmic. I am using ssh-keyscan(1) for its intended purpose: building an ssh_known_hosts file for a large network. Most of the hosts on this network are well-maintained systems, with properly-functioning SSH servers, and present no difficulty to the program. However, a handful of hosts are barely alive, with SSH servers that are not exactly in good working order. ssh-keyscan(1) currently will scan these systems, encounter some form of error, and then---right here is the problem---exit in the middle of the scan. The last bit of stderr output may look like # A.B.C.D SSH-2.0-OpenSSH_4.3 # A.B.C.E SSH-2.0-OpenSSH_4.3 # A.B.C.F SSH-1.99-OpenSSH_3.7p1 Connection closed by A.B.C.F or # A.B.C.D SSH-2.0-OpenSSH_4.1 # A.B.C.E SSH-2.0-OpenSSH_4.1 # A.B.C.F SSH-2.0-mpSSH_0.1.0 Received disconnect from A.B.C.F: 10: Protocol error or # A.B.C.D SSH-2.0-OpenSSH_4.4p1 # A.B.C.E SSH-2.0-OpenSSH_5.0p1 # A.B.C.F SSH-2.0-mpSSH_0.1.0 Received disconnect from A.B.C.F: 11: SSH Disabled (These are the different failure modes I've observed to date) ssh-keyscan(1) needs to be robust to these kinds of errors---simply make a note of them, and continue on with the scan. I don't want to have to find out which systems are misbehaving by running and re- running the scan (each run yields at most one bad host, obviously), nor manually edit out the few bad apples from the input list of hosts (especially considering that this particular subset can change over time). Neither is feasible when the number of hosts being scanned is very large. To manage notifications about this bug go to: https://bugs.launchpad.net/openssh/+bug/483928/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp