ssh_exchange_identification: Connection closed by remote host

Colegas, estou tentando fazer um ssh de uma máquina qualquer para o meu servidor que eu chamo de nxserver, mas quando eu vou dar um ssh, ele me retorna este erro:

ssh_exchange_identification: Connection closed by remote host

seguem alguns dos meus arquivos para análise:

--- começo de hosts.allow ---

# hosts.allow This file describes the names of the hosts which are
# allowed to use the local INET services, as decided by
# the '/usr/sbin/tcpd' server.
#
# Version: @(#)/etc/hosts.allow 1.00 05/28/93
#
# Author: Fred N. van Kempen, <[email protected]
#
#

ALL : ALL : ALLOW

# End of hosts.allow.

--- final de hosts.allow ---

--- começo de hosts.deny ---

#
# hosts.deny This file describes the names of the hosts which are
# *not* allowed to use the local INET services, as decided
# by the '/usr/sbin/tcpd' server.
#
# Version: @(#)/etc/hosts.deny 1.00 05/28/93
#
# Author: Fred N. van Kempen, <[email protected]
#
#

# End of hosts.deny.

--- final de hosts.deny ---

--- começo de /etc/ssh/sshd_config ---

# $OpenBSD: sshd_config,v 1.72 2005/07/25 11:59:40 markus Exp $

# This is the sshd server system-wide configuration file. See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented. Uncommented options change a
# default value.

#Port 22
#Protocol 2,1
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::

# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key

# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 768

# Logging
# obsoletes QuietMode and FascistLogging
#SyslogFacility AUTH
#LogLevel INFO

# Authentication:

#LoginGraceTime 2m
#PermitRootLogin yes
#StrictModes yes
#MaxAuthTries 6

#RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile .ssh/authorized_keys

# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes

# To disable tunneled clear text passwords, change to no here!
#PasswordAuthentication yes
#PermitEmptyPasswords no

# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes

# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication mechanism.
# Depending on your PAM configuration, this may bypass the setting of
# PasswordAuthentication, PermitEmptyPasswords, and
# "PermitRootLogin without-password". If you just want the PAM account and
# session checks to run without PAM authentication, then enable this but set
# ChallengeResponseAuthentication=no
#UsePAM no

#AllowTcpForwarding yes
#GatewayPorts no
X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#PrintMotd yes
#PrintLastLog yes
#TCPKeepAlive yes
#UseLogin no
#UsePrivilegeSeparation yes
#PermitUserEnvironment no
#Compression delayed
#ClientAliveInterval 0
#ClientAliveCountMax 3
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10

# no default banner path
#Banner /some/path

# override default of no subsystems
Subsystem sftp /usr/libexec/sftp-server

# AllowUsers to login with NX server
AllowUsers nx looknet

--- final de /etc/ssh/sshd_config ---

--- listagem de arquivos em /etc/ssh ---

root@nxserver:/etc/ssh# ls -laF
total 176
drwxr-xr-x 2 root root 4096 2006-11-29 21:30 ./
drwxr-xr-x 24 root root 4096 2006-11-29 17:30 ../
-rw-r--r-- 1 root root 132839 2005-09-01 11:46 moduli
-rw-r--r-- 1 root root 1292 2005-09-01 11:46 ssh_config
-rw------- 1 root root 1192 2006-11-22 17:06 ssh_host_dsa_key
-rw-r--r-- 1 root root 1115 2006-11-22 17:06 ssh_host_dsa_key.pub
-rw------- 1 root root 976 2006-11-22 17:05 ssh_host_key
-rw-r--r-- 1 root root 640 2006-11-22 17:05 ssh_host_key.pub
-rw------- 1 root root 1675 2006-11-22 17:06 ssh_host_rsa_key
-rw-r--r-- 1 root root 395 2006-11-22 17:06 ssh_host_rsa_key.pub
-rw-r--r-- 1 root root 2944 2006-11-29 21:20 sshd_config

--- fim da listagem ---

Estou utilizando Slackware 10.2, kernel 2.4.31

Essa mensagem geralmente e causada pelo tcpwrapper

limpe todo conteudo do seu hosts.allow e hosts.deny

que deve resolver o problema.

A nao ser e claro que vc esteja usando algo neles..

outra coisa que vc pode fazer

e dar um ssh com o parametro -v
pra ajudar a debugar e descobrir qual pode ser o erro :)

Colega,

Mas no meu arquivo hosts.allow só tem o seguinte parâmetro:

ALL : ALL : ALLOW

que foi posta justamente porque eu não conseguia fazer conexões via ssh como o arquivo totalmente em branco, então pesquisando no São Google eu vi que precisava adicionar algo no hosts.allow como "sshd : ALL : ALLOW" ou "ALL : ALL : ALLOW" que era pra permitir os acessos ao host.

mas respondendo mais diretamente à sua pergunta, não funcionou limpar os arquivos hosts.(allow|deny)

fico no aguardo de mais alternativas, se você souber de outra coisa que eu possa tentar, agradeço, valeu.

localmente ssh na propria maquina funciona ?


vc ja tentou dar um ssh 127.0.0.1

na maquina que vc nao consegue acessar ?

Olá colega, ssh local também não funciona:

root@nxserver:~/.ssh# ssh 127.0.0.1
ssh_exchange_identification: Connection closed by remote host

será que eu poderia tentar algo mais?

atualiza a versao do seu ssh que vai resolver !!

da um ssh -v 127.0.0.1

e cole tudo aqui

Colega, eis a resposta de "ssh -v 127.0.0.1"

OpenSSH_4.2p1, OpenSSL 0.9.7g 11 Apr 2005
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to 127.0.0.1 [127.0.0.1] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_dsa type -1
ssh_exchange_identification: Connection closed by remote host


Obrigado pela força,

Guilherme