Eu tenho uma máquina remota (IP XX.XX.XX.XX ) que executa um aplicativo escrito em python / cherrypy que abre uma porta para conexões http na interface de loopback. Se eu fizer login na máquina remota (usando ssh) e depois executar
curl http://127.0.0.1:8021
tudo funciona bem. Mas, quando eu configurei um túnel da minha máquina local usando
ssh -L 6868:XX.XX.XX.XX:8021 -fN XX.XX.XX.XX
e, em seguida, execute
curl http://localhost:6868
ou
curl http://127.0.0.1:6868
Eu recebo esta mensagem
curl: (52) Empty reply from server
ssh mostra esta mensagem no terminal onde criei o túnel
channel 2: open failed: connect failed: Connection refused
Para testar, alterei o aplicativo para abrir a porta na interface de rede real (XX.XX.XX.XX em vez de 127.0.0.1) e usei o curl de outra máquina na mesma rede remota e funcionou. No entanto, tentar criar um túnel entre as duas máquinas remotas produziu os mesmos resultados que entre um servidor remoto e minha máquina local.
Eu tentei me certificar de que o problema não é o firewall, então eu corri
iptables -A INPUT -d 127.0.0.1/32 -i lo -j ACCEPT
que eu acho que é o suficiente, mas não tenho certeza. Aqui está o ssh -v output
[____@YYYY ~]$ ssh -vvL 6868:XX.XX.XX.XX:8021 -fN XX.XX.XX.XX
OpenSSH_5.4p1, OpenSSL 1.0.0-fips 29 Mar 2010
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to [XX.XX.XX.XX] port 22.
debug1: Connection established.
debug1: identity file /home/____/.ssh/id_rsa type -1
debug1: identity file /home/____/.ssh/id_rsa-cert type -1
debug1: identity file /home/____/.ssh/id_dsa type -1
debug1: identity file /home/____/.ssh/id_dsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.4
debug1: match: OpenSSH_5.4 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.4
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: [email protected],[email protected],ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_setup: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_setup: found hmac-md5
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 117/256
debug2: bits set: 510/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'XX.XX.XX.XX' is known and matches the RSA host key.
debug1: Found key in /home/____/.ssh/known_hosts:5
debug2: bits set: 514/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/____/.ssh/id_rsa ((nil))
debug2: key: /home/____/.ssh/id_dsa ((nil))
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password,hostbased
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more information
Credentials cache file '/tmp/krb5cc_524' not found
debug1: Unspecified GSS failure. Minor code may provide more information
Credentials cache file '/tmp/krb5cc_524' not found
debug1: Unspecified GSS failure. Minor code may provide more information
debug2: we did not send a packet, disable method
debug1: Next authentication method: publickey
debug1: Trying private key: /home/____/.ssh/id_rsa
debug1: Trying private key: /home/____/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug1: Next authentication method: password
[email protected]'s password:
debug2: we sent a password packet, wait for reply
debug1: Authentication succeeded (password).
debug1: Local connections to LOCALHOST:6868 forwarded to remote address XX.XX.XX.XX:8021
debug1: Local forwarding listening on ::1 port 6868.
debug2: fd 4 setting O_NONBLOCK
debug1: channel 0: new [port listener]
debug1: Local forwarding listening on 127.0.0.1 port 6868.
debug2: fd 5 setting O_NONBLOCK
debug1: channel 1: new [port listener]
debug1: Requesting [email protected]
debug1: Entering interactive session.
debug1: Connection to port 6868 forwarding to XX.XX.XX.XX port 8021 requested.
debug2: fd 6 setting TCP_NODELAY
debug2: fd 6 setting O_NONBLOCK
debug1: channel 2: new [direct-tcpip]
channel 2: open failed: connect failed: Connection refused
debug2: channel 2: zombie
debug2: channel 2: garbage collecting
debug1: channel 2: free: direct-tcpip: listening port 6868 for XX.XX.XX.XX port 8021, connect from 127.0.0.1 port 47048, nchannels 3
A conexão do seu servidor para XX.XX.XX.XX: 8021 é recusada.
Se um programa estiver configurado para escutar na interface de loopback, ele responderá somente a conexões nos endereços da interface de loopback (127.0.0.1 e :: 1), não em quaisquer outros endereços que o mesmo computador tenha.
Você precisa usar:
ssh -L 6868:127.0.0.1:8021 -fN XX.XX.XX.XX
Observe que o destino do túnel é da perspectiva do servidor SSH.
Tags ssh linux ssh-tunnel