I am running Ubuntu 10.10 on a remote box. I ssh to it everyday without issues but today out of the blue, I get the following error: ssh_exchange_identification: Connection closed by remote host If I connect with -vv, I get the following: OpenSSH_5.6p1, OpenSSL 0.9.8r 8 Feb 2011 debug1: Reading configuration data /Users/bla/.ssh/config debug1: Applying options for ubuntu-server debug1: Reading configuration data /etc/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to ubuntu-server.com [123.123.123.123] port 22. debug1: Connection established. debug2: key_type_from_name: unknown key type '-----BEGIN' debug2: key_type_from_name: unknown key type '-----END' debug1: identity file /Users/bla/.ssh/id_rsa type -1 debug1: identity file /Users/bla/.ssh/id_rsa-cert type -1 ssh_exchange_identification: Connection closed by remote host If I remove the key, I get the exact same output (sans "debug2: key_type_...). I've managed to log in physically and checked my hosts.allow and hosts.deny but they have no entries. I tried removing and reinstalling OpenSSH, checked authorized_keys and ~/.ssh permissions and tried connecting from other computers only to get the same error. I'm at my wits end, any help would be greatly appreciated.