我尝试每晚自动下载 Cisco 交换机配置，以便对其进行版本控制。我用来测试的命令是
ssh -vvv -t -t -o nethelp@switch 'show running-config' > ~/switch-interactive-config.txt 2>&1
当我在 Bash shell 中运行此命令时，完整的运行配置会输出到 switch-config.txt，但当我将该行放入 crontab 时，只有一半的配置被保存。cron 条目如下所示：
05 15 * * * ssh -vvv -t -t -o nethelp@switch 'show running-config' > ~/switch-crontab-config.txt 2>&1
使用的交换机和IOS是
bootdisk:c6880x-ipservicesk9-mz.SPA.152-1.SY5.bin
CLI 连接日志文件的相关部分：
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to switch [192.168.150.1] port 22.
debug1: Connection established.
debug1: identity file /home/nethelp/.ssh/identity type -1
debug3: Not a RSA1 key file /home/nethelp/.ssh/id_rsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /home/nethelp/.ssh/id_rsa type 1
debug1: identity file /home/nethelp/.ssh/id_dsa type -1
debug1: loaded 3 keys
debug1: Remote protocol version 2.0, remote software version Cisco-1.25
debug1: no match: Cisco-1.25
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.3
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: 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,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,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-sha1,diffie-hellman-group14-sha1
debug2: kex_parse_kexinit: ssh-rsa
debug2: kex_parse_kexinit: aes256-ctr
debug2: kex_parse_kexinit: aes256-ctr
debug2: kex_parse_kexinit: hmac-sha1
debug2: kex_parse_kexinit: hmac-sha1
debug2: kex_parse_kexinit: none
debug2: kex_parse_kexinit: none
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_init: found hmac-sha1
debug1: kex: server->client aes256-ctr hmac-sha1 none
debug2: mac_init: found hmac-sha1
debug1: kex: client->server aes256-ctr hmac-sha1 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<4096<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 246/512
debug2: bits set: 2104/4096
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: check_host_in_hostfile: filename /home/nethelp/.ssh/known_hosts2
debug3: check_host_in_hostfile: filename /etc/ssh/ssh_known_hosts2
debug3: check_host_in_hostfile: filename /home/nethelp/.ssh/known_hosts2
debug3: check_host_in_hostfile: filename /etc/ssh/ssh_known_hosts2
debug3: check_host_in_hostfile: filename /home/nethelp/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 15
debug3: check_host_in_hostfile: filename /home/nethelp/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 9
debug1: Host 'switch' is known and matches the RSA host key.
debug1: Found key in /home/nethelp/.ssh/known_hosts:15
debug2: bits set: 2024/4096
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug2: cipher_init: set keylen (16 -> 32)
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: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/nethelp/.ssh/identity ((nil))
debug2: key: /home/nethelp/.ssh/id_rsa (0x2ab9222d6af0)
debug2: key: /home/nethelp/.ssh/id_dsa ((nil))
debug1: Authentications that can continue: publickey,keyboard-interactive,password
debug3: start over, passed a different list publickey,keyboard-interactive,password
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/nethelp/.ssh/identity
debug3: no such identity: /home/nethelp/.ssh/identity
debug1: Offering public key: /home/nethelp/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug2: input_userauth_pk_ok: SHA1 fp 86:90:57:57:2f:bf:8f:af:47:75:f5:ee:14:15:72:31:b4:24:a1:39
debug3: sign_and_send_pubkey
debug1: read PEM private key done: type RSA
debug1: Authentication succeeded (publickey).
debug2: fd 5 setting O_NONBLOCK
debug3: fd 6 is O_NONBLOCK
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug1: Entering interactive session.
debug2: callback start
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 0
debug3: tty_make_modes: ospeed 38400
debug3: tty_make_modes: ispeed 38400
debug3: tty_make_modes: 1 3
debug3: tty_make_modes: 2 28
debug3: tty_make_modes: 3 127
debug3: tty_make_modes: 4 21
debug3: tty_make_modes: 5 4
debug3: tty_make_modes: 6 0
debug3: tty_make_modes: 7 0
debug3: tty_make_modes: 8 17
debug3: tty_make_modes: 9 19
debug3: tty_make_modes: 10 26
debug3: tty_make_modes: 12 18
debug3: tty_make_modes: 13 23
debug3: tty_make_modes: 14 22
debug3: tty_make_modes: 18 15
debug3: tty_make_modes: 30 0
debug3: tty_make_modes: 31 0
debug3: tty_make_modes: 32 0
debug3: tty_make_modes: 33 0
debug3: tty_make_modes: 34 0
debug3: tty_make_modes: 35 0
debug3: tty_make_modes: 36 1
debug3: tty_make_modes: 37 0
debug3: tty_make_modes: 38 1
debug3: tty_make_modes: 39 0
debug3: tty_make_modes: 40 0
debug3: tty_make_modes: 41 0
debug3: tty_make_modes: 50 1
debug3: tty_make_modes: 51 1
debug3: tty_make_modes: 52 0
debug3: tty_make_modes: 53 1
debug3: tty_make_modes: 54 1
debug3: tty_make_modes: 55 1
debug3: tty_make_modes: 56 0
debug3: tty_make_modes: 57 0
debug3: tty_make_modes: 58 0
debug3: tty_make_modes: 59 1
debug3: tty_make_modes: 60 1
debug3: tty_make_modes: 61 1
debug3: tty_make_modes: 62 0
debug3: tty_make_modes: 70 1
debug3: tty_make_modes: 71 0
debug3: tty_make_modes: 72 1
debug3: tty_make_modes: 73 0
debug3: tty_make_modes: 74 0
debug3: tty_make_modes: 75 0
debug3: tty_make_modes: 90 1
debug3: tty_make_modes: 91 1
debug3: tty_make_modes: 92 0
debug3: tty_make_modes: 93 0
debug1: Sending environment.
debug3: Ignored env HOSTNAME
debug3: Ignored env SHELL
debug3: Ignored env TERM
debug3: Ignored env HISTSIZE
debug3: Ignored env USER
debug3: Ignored env LS_COLORS
debug3: Ignored env MAIL
debug3: Ignored env PATH
debug3: Ignored env INPUTRC
debug3: Ignored env PWD
debug1: Sending env LANG = en_US.UTF-8
debug2: channel 0: request env confirm 0
debug3: Ignored env SSH_ASKPASS
debug3: Ignored env SHLVL
debug3: Ignored env HOME
debug3: Ignored env LOGNAME
debug3: Ignored env LESSOPEN
debug3: Ignored env G_BROKEN_FILENAMES
debug3: Ignored env _
debug3: Ignored env OLDPWD
debug1: Sending command: show running-config
debug2: channel 0: request exec confirm 0
debug2: fd 3 setting TCP_NODELAY
debug2: callback done
debug2: channel 0: open confirm rwindow 8192 rmax 4096
... COMPLETE SWITCH CONFIG FOLLOWS ...
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug2: channel 0: rcvd eof
debug2: channel 0: output open -> drain
debug2: channel 0: obuf empty
debug2: channel 0: close_write
debug2: channel 0: output drain -> closed
debug2: channel 0: rcvd close
debug2: channel 0: close_read
debug2: channel 0: input open -> closed
debug3: channel 0: will not send data after close
debug2: channel 0: almost dead
debug2: channel 0: gc: notify user
debug2: channel 0: gc: user detached
debug2: channel 0: send close
debug2: channel 0: is dead
debug2: channel 0: garbage collecting
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
#0 client-session (t4 r3 i3/0 o3/0 fd -1/-1 cfd -1)
debug3: channel 0: close_fds r -1 w -1 e 6 c -1
debug1: fd 1 clearing O_NONBLOCK
debug3: fd 2 is not O_NONBLOCK
Connection to switch closed by remote host.
Connection to switch closed.
debug1: Transferred: stdin 0, stdout 0, stderr 81 bytes in 1.8 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 44.5
debug1: Exit status 0
从 cron 运行时，会保存不完整的配置，日志文件如下所示：
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to switch [192.168.150.1] port 22.
debug1: Connection established.
debug1: identity file /home/nethelp/.ssh/identity type -1
debug3: Not a RSA1 key file /home/nethelp/.ssh/id_rsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /home/nethelp/.ssh/id_rsa type 1
debug1: identity file /home/nethelp/.ssh/id_dsa type -1
debug1: loaded 3 keys
debug1: Remote protocol version 2.0, remote software version Cisco-1.25
debug1: no match: Cisco-1.25
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.3
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: 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,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,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-sha1,diffie-hellman-group14-sha1
debug2: kex_parse_kexinit: ssh-rsa
debug2: kex_parse_kexinit: aes256-ctr
debug2: kex_parse_kexinit: aes256-ctr
debug2: kex_parse_kexinit: hmac-sha1
debug2: kex_parse_kexinit: hmac-sha1
debug2: kex_parse_kexinit: none
debug2: kex_parse_kexinit: none
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_init: found hmac-sha1
debug1: kex: server->client aes256-ctr hmac-sha1 none
debug2: mac_init: found hmac-sha1
debug1: kex: client->server aes256-ctr hmac-sha1 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<4096<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 265/512
debug2: bits set: 2075/4096
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: check_host_in_hostfile: filename /home/nethelp/.ssh/known_hosts2
debug3: check_host_in_hostfile: filename /etc/ssh/ssh_known_hosts2
debug3: check_host_in_hostfile: filename /home/nethelp/.ssh/known_hosts2
debug3: check_host_in_hostfile: filename /etc/ssh/ssh_known_hosts2
debug3: check_host_in_hostfile: filename /home/nethelp/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 15
debug3: check_host_in_hostfile: filename /home/nethelp/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 9
debug1: Host 'switch' is known and matches the RSA host key.
debug1: Found key in /home/nethelp/.ssh/known_hosts:15
debug2: bits set: 2051/4096
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug2: cipher_init: set keylen (16 -> 32)
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: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/nethelp/.ssh/identity ((nil))
debug2: key: /home/nethelp/.ssh/id_rsa (0x2b76847cdaf0)
debug2: key: /home/nethelp/.ssh/id_dsa ((nil))
debug1: Authentications that can continue: publickey,keyboard-interactive,password
debug3: start over, passed a different list publickey,keyboard-interactive,password
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/nethelp/.ssh/identity
debug3: no such identity: /home/nethelp/.ssh/identity
debug1: Offering public key: /home/nethelp/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug2: input_userauth_pk_ok: SHA1 fp 86:90:57:57:2f:bf:8f:af:47:75:f5:ee:14:15:72:31:b4:24:a1:39
debug3: sign_and_send_pubkey
debug1: read PEM private key done: type RSA
debug1: Authentication succeeded (publickey).
debug2: fd 4 setting O_NONBLOCK
debug2: fd 5 setting O_NONBLOCK
debug3: fd 6 is O_NONBLOCK
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug1: Entering interactive session.
tcgetattr: Invalid argument
debug2: callback start
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 0
debug3: tty_make_modes: ospeed 0
debug3: tty_make_modes: ispeed 0
debug3: tty_make_modes: 1 0
debug3: tty_make_modes: 2 0
debug3: tty_make_modes: 3 0
debug3: tty_make_modes: 4 0
debug3: tty_make_modes: 5 0
debug3: tty_make_modes: 6 0
debug3: tty_make_modes: 7 0
debug3: tty_make_modes: 8 0
debug3: tty_make_modes: 9 0
debug3: tty_make_modes: 10 0
debug3: tty_make_modes: 12 0
debug3: tty_make_modes: 13 0
debug3: tty_make_modes: 14 0
debug3: tty_make_modes: 18 0
debug3: tty_make_modes: 30 0
debug3: tty_make_modes: 31 0
debug3: tty_make_modes: 32 0
debug3: tty_make_modes: 33 0
debug3: tty_make_modes: 34 0
debug3: tty_make_modes: 35 0
debug3: tty_make_modes: 36 0
debug3: tty_make_modes: 37 0
debug3: tty_make_modes: 38 0
debug3: tty_make_modes: 39 0
debug3: tty_make_modes: 40 0
debug3: tty_make_modes: 41 0
debug3: tty_make_modes: 50 0
debug3: tty_make_modes: 51 0
debug3: tty_make_modes: 52 0
debug3: tty_make_modes: 53 0
debug3: tty_make_modes: 54 0
debug3: tty_make_modes: 55 0
debug3: tty_make_modes: 56 0
debug3: tty_make_modes: 57 0
debug3: tty_make_modes: 58 0
debug3: tty_make_modes: 59 0
debug3: tty_make_modes: 60 0
debug3: tty_make_modes: 61 0
debug3: tty_make_modes: 62 0
debug3: tty_make_modes: 70 0
debug3: tty_make_modes: 71 0
debug3: tty_make_modes: 72 0
debug3: tty_make_modes: 73 0
debug3: tty_make_modes: 74 0
debug3: tty_make_modes: 75 0
debug3: tty_make_modes: 90 0
debug3: tty_make_modes: 91 0
debug3: tty_make_modes: 92 0
debug3: tty_make_modes: 93 0
debug1: Sending environment.
debug3: Ignored env HOSTNAME
debug3: Ignored env TERM
debug3: Ignored env SHELL
debug3: Ignored env HISTSIZE
debug3: Ignored env USER
debug3: Ignored env PATH
debug3: Ignored env MAIL
debug3: Ignored env PWD
debug3: Ignored env INPUTRC
debug1: Sending env LANG = en_US.UTF-8
debug2: channel 0: request env confirm 0
debug3: Ignored env SSH_ASKPASS
debug3: Ignored env HOME
debug3: Ignored env SHLVL
debug3: Ignored env LOGNAME
debug3: Ignored env LESSOPEN
debug3: Ignored env G_BROKEN_FILENAMES
debug3: Ignored env _
debug1: Sending command: show running-config
debug2: channel 0: request exec confirm 0
debug2: fd 3 setting TCP_NODELAY
debug2: callback done
debug2: channel 0: open confirm rwindow 8192 rmax 4096
debug2: channel 0: read<=0 rfd 4 len 0
debug2: channel 0: read failed
debug2: channel 0: close_read
debug2: channel 0: input open -> drain
debug2: channel 0: ibuf empty
debug2: channel 0: send eof
debug2: channel 0: input drain -> closed
... HALF OF THE SWITCH CONFIGURATION FOLLOWS (about 100KB of 200KB) ...
debug2: channel 0: rcvd eof
debug2: channel 0: output open -> drain
debug2: channel 0: obuf empty
debug2: channel 0: close_write
debug2: channel 0: output drain -> closed
debug2: channel 0: rcvd close
debug3: channel 0: will not send data after close
debug2: channel 0: almost dead
debug2: channel 0: gc: notify user
debug2: channel 0: gc: user detached
debug2: channel 0: send close
debug2: channel 0: is dead
debug2: channel 0: garbage collecting
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
#0 client-session (t4 r3 i3/0 o3/0 fd -1/-1 cfd -1)
debug3: channel 0: close_fds r -1 w -1 e 6 c -1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
debug3: fd 2 is not O_NONBLOCK
Connection to switch closed by remote host.
Connection to switch closed.
debug1: Transferred: stdin 0, stdout 0, stderr 81 bytes in 1.4 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 56.4
debug1: Exit status 0
当我比较 SSH 输出时，令我印象深刻的是，在伪 tty 模式下，ospeed 和 ispeed 设置为 0，而在交互模式下则为 38400。
有人能解释一下为什么我通过 cron 作业只能获取部分配置吗？