Estou operando um dispositivo incorporado executando o núcleo do Linux. Eu tenho OpenSHH_4.9p1 instalado em execução no modo de depuração e tentando estabelecer uma conexão SSH usando PuTTY. Após a tela de login, tudo está funcionando bem e rápido. Minha lentidão ocorre durante a conexão inicial antes que a tela de login seja exibida. Parece que estou tendo problemas em alguns locais importantes, mas não consigo identificar o problema. Eu tenho um atraso de conexão que varia de 20 a 30 segundos, o que consome muito do tempo dos meus clientes.
[root@NGCP ssh]# /usr/sbin/sshd -dddd -p 22
debug2: load_server_config: filename /etc/ssh/sshd_config
debug2: load_server_config: done config len = 267
debug2: parse_server_config: config /etc/ssh/sshd_config len 267
debug3: /etc/ssh/sshd_config:96 setting UseDNS no
debug3: /etc/ssh/sshd_config:105 setting Subsystem sftp /usr/libexec/sftp-server
debug3: checking syntax for 'Match user railcomm'
debug3: checking syntax for 'Match user maintenance'
debug1: sshd version OpenSSH_4.9p1
debug1: private host key: #0 type 0 RSA1
debug3: Not a RSA1 key file /etc/ssh/ssh_host_rsa_key.
debug1: read PEM private key done: type RSA
debug1: private host key: #1 type 1 RSA
debug3: Not a RSA1 key file /etc/ssh/ssh_host_dsa_key.
debug1: read PEM private key done: type DSA
debug1: private host key: #2 type 2 DSA
debug1: rexec_argv[0]='/usr/sbin/sshd'
debug1: rexec_argv[1]='-dddd'
debug1: rexec_argv[2]='-p'
debug1: rexec_argv[3]='22'
socket: Address family not supported by protocol
debug2: fd 3 setting O_NONBLOCK
debug1: Bind to port 22 on 0.0.0.0.
Server listening on 0.0.0.0 port 22.
Generating 768 bit RSA key. <-- FOUR SECONDS
RSA key generation complete.
debug3: fd 4 is not O_NONBLOCK
debug1: Server will not fork when running in debugging mode.
debug3: send_rexec_state: entering fd = 7 config len 267
debug3: ssh_msg_send: type 0
debug3: send_rexec_state: done
debug1: rexec start in 4 out 4 newsock 4 pipe -1 sock 7
debug1: inetd sockets after dupping: 3, 3
Connection from 10.40.50.156 port 59565
debug1: Client protocol version 2.0; client software version PuTTY_Release_0.66
debug1: no match: PuTTY_Release_0.66
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-1.99-OpenSSH_4.9
debug2: fd 3 setting O_NONBLOCK
debug2: Network child is on pid 1051
debug3: preauth child monitor started
debug3: mm_request_receive entering
debug3: privsep user:group 74:74
debug1: permanently_set_uid: 74/74
debug1: list_hostkey_types: ssh-rsa,ssh-dss
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: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-ctr,aes192-ctr,aes256-ctr
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: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,rsa2048-sha256,rsa1024-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes256-ctr,aes256-cbc,[email protected],aes192-ctr,aes192-cbc,aes128-ctr,aes128-cbc,blowfish-ctr,blowfish-cbc,3des-ctr,3des-cbc,arcfour256,arcfour128
debug2: kex_parse_kexinit: aes256-ctr,aes256-cbc,[email protected],aes192-ctr,aes192-cbc,aes128-ctr,aes128-cbc,blowfish-ctr,blowfish-cbc,3des-ctr,3des-cbc,arcfour256,arcfour128
debug2: kex_parse_kexinit: hmac-sha2-256,hmac-sha1,hmac-sha1-96,hmac-md5
debug2: kex_parse_kexinit: hmac-sha2-256,hmac-sha1,hmac-sha1-96,hmac-md5
debug2: kex_parse_kexinit: none,zlib
debug2: kex_parse_kexinit: none,zlib
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-sha1
debug1: kex: client->server aes256-ctr hmac-sha1 none
debug2: mac_setup: found hmac-sha1
debug1: kex: server->client aes256-ctr hmac-sha1 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST received
debug3: mm_request_send entering: type 0
debug3: monitor_read: checking request 0
debug3: mm_answer_moduli: got parameters: 1024 4096 8192
debug3: mm_choose_dh: waiting for MONITOR_ANS_MODULI
debug3: mm_request_receive_expect entering: type 1
debug3: mm_request_receive entering
debug3: mm_request_send entering: type 1
debug3: mm_choose_dh: remaining 0
debug1: SSH2_MSG_KEX_DH_GEX_GROUP sent
debug2: monitor_read: 0 used once, disabling now
debug3: mm_request_receive entering <-- FIVE SECONDS
debug2: dh_gen_key: priv key bits set: 264/512
debug2: bits set: 1949/4096
debug1: expecting SSH2_MSG_KEX_DH_GEX_INIT
debug2: bits set: 2023/4096 <-- FIVE SECONDS
debug3: mm_key_sign entering
debug3: mm_request_send entering: type 4
debug3: monitor_read: checking request 4
debug3: mm_answer_sign
debug3: mm_key_sign: waiting for MONITOR_ANS_SIGN
debug3: mm_request_receive_expect entering: type 5
debug3: mm_request_receive entering
debug3: mm_answer_sign: signature 0x8005da00(271)
debug3: mm_request_send entering: type 5
debug1: SSH2_MSG_KEX_DH_GEX_REPLY sent
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug2: cipher_init: set keylen (16 -> 32)
debug2: monitor_read: 4 used once, disabling now
debug3: mm_request_receive entering
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug2: cipher_init: set keylen (16 -> 32)
debug1: SSH2_MSG_NEWKEYS received
debug1: KEX done