我在远程机器上运行 Ubuntu 10.10。我每天 ssh 都没有问题，但今天突然出现以下错误：
ssh_exchange_identification: Connection closed by remote host
如果我与 连接-vv，我会得到以下信息：
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: …