Aktivér fejlretningstilstand i SSH for at foretage fejlfinding af forbindelsesproblemer
I denne artikel viser vi dig, hvordan du aktiverer fejlretningstilstand, mens du kører SSH i Linux. Dette giver dig mulighed for at se, hvad der faktisk udfolder sig, når du udfører en ssh-kommando for at oprette forbindelse til en ekstern Linux-server ved hjælp af den detaljerede tilstand eller fejlretningstilstand.
Ssh-klientens switch -v
giver dig mulighed for at køre ssh i detaljeret tilstand, der udskriver fejlretningsoplysninger om SSH-forbindelsesfremgang, hvilket virkelig er nyttigt til fejlretning af forbindelser, godkendelse og eventuelle konfigurationsproblemer. Der er forskellige niveauer af bredhed; brug af flere -v
-flagg øger bredden (maksimumniveauet er 3).
Den følgende kommando kører SSH i første niveau af ordlighedsgrad, hvilket giver os masser af fejlretningsoplysninger som vist.
[email ~ $ ssh -v [email
OpenSSH_7.2p2 Ubuntu-4ubuntu2.2, OpenSSL 1.0.2g-fips 1 Mar 2016 debug1: Reading configuration data /home/aaronkilik/.ssh/config debug1: /home/aaronkilik/.ssh/config line 18: Applying options for * debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug1: Connecting to 192.168.56.10 [192.168.56.10] port 22. debug1: Connection established. debug1: identity file /home/aaronkilik/.ssh/id_rsa type 1 debug1: key_load_public: No such file or directory debug1: identity file /home/aaronkilik/.ssh/id_rsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/aaronkilik/.ssh/id_dsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/aaronkilik/.ssh/id_dsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/aaronkilik/.ssh/id_ecdsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/aaronkilik/.ssh/id_ecdsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/aaronkilik/.ssh/id_ed25519 type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/aaronkilik/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.2 debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4 debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000 debug1: Authenticating to 192.168.56.10:22 as 'tecmint' debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: algorithm: [email debug1: kex: host key algorithm: ecdsa-sha2-nistp256 debug1: kex: server->client cipher: [email MAC: compression: [email debug1: kex: client->server cipher: [email MAC: compression: [email debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: ecdsa-sha2-nistp256 SHA256:1778erqyug4tHJa7D6y/Ep4UWsUtNEOBSMaj32k9oO8 debug1: Host '192.168.56.10' is known and matches the ECDSA host key. debug1: Found key in /home/aaronkilik/.ssh/known_hosts:8 debug1: rekey after 134217728 blocks debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: rekey after 134217728 blocks debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_EXT_INFO received debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512> debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password debug1: Next authentication method: publickey debug1: Offering RSA public key: /home/aaronkilik/.ssh/id_rsa debug1: Server accepts key: pkalg rsa-sha2-512 blen 279 debug1: Enabling compression at level 6. debug1: Authentication succeeded (publickey). Authenticated to 192.168.56.10 ([192.168.56.10]:22). debug1: channel 0: new [client-session] debug1: Requesting [email debug1: Entering interactive session. debug1: pledge: network debug1: client_input_global_request: rtype [email want_reply 0 debug1: Sending environment. debug1: Sending env LC_PAPER = lg_UG.UTF-8 debug1: Sending env LC_ADDRESS = lg_UG.UTF-8 debug1: Sending env LC_MONETARY = lg_UG.UTF-8 debug1: Sending env LC_NUMERIC = lg_UG.UTF-8 debug1: Sending env LC_TELEPHONE = lg_UG.UTF-8 debug1: Sending env LC_IDENTIFICATION = lg_UG.UTF-8 debug1: Sending env LANG = en_US.UTF-8 debug1: Sending env LC_MEASUREMENT = lg_UG.UTF-8 debug1: Sending env LC_NAME = lg_UG.UTF-8 Last login: Sat Jan 6 16:20:11 2018 from 192.168.56.1
Når du prøver at logge ud eller afslutte sessionen, vil du også se fejlretningsmeddelelser som vist.
[[email ~]$ exit logout debug1: client_input_channel_req: channel 0 rtype exit-status reply 0 debug1: client_input_channel_req: channel 0 rtype [email reply 0 debug1: channel 0: free: client-session, nchannels 1 Connection to 192.168.56.10 closed. Transferred: sent 3392, received 3120 bytes, in 118.1 seconds Bytes per second: sent 28.7, received 26.4 debug1: Exit status 0 debug1: compress outgoing: raw data 1159, compressed 573, factor 0.49 debug1: compress incoming: raw data 573, compressed 1159, factor 2.02
Dernæst kan du aktivere yderligere (niveau 2 og 3) detaljerethed for endnu flere fejlretningsmeddelelser som vist.
$ ssh -vv [email $ ssh -vvv [email
Det er det! For mere brug af SSH, læs disse følgende relaterede artikler.
- Sådan finder du alle mislykkede SSH-loginforsøg i Linux
- Sådan deaktiveres SSH-rodindlogning i Linux
- SSH adgangskodeløst login ved hjælp af SSH Keygen i 5 nemme trin
- Sådan afbrydes inaktive eller inaktive SSH-forbindelser i Linux
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