Ich habe ein seltsames Problem, wenn ich mich mit mehreren Servern verbinde und SSH zu ihnen verwende. An zufälligen Punkten während der Verbindungsphase oder nach einer Weile läuft die Verbindung ab.
Das Problem tritt sowohl auf meinem Mac als auch auf meinem iPhone (bei Verwendung der Termius-App) auf.
Dies passiert sowohl bei Verwendung eines SSH-Schlüssels als auch bei Verwendung eines Kennworts, jedoch häufiger bei Verwendung eines SSH-Schlüssels.
Das Problem tritt nur auf, wenn ich das Internet im Büro verwende. Wenn ich 4G von meinem Telefon aus verwende, verschwindet das Problem. Die Verwendung des Telefons als mobiler Hotspot, der mit dem Bürorouter verbunden ist, funktioniert ebenfalls, das Problem scheint also bei unserem ISP zu liegen.
Ich habe mit dem Support des ISP gesprochen und sie können nichts tun.
Dies passierte gestern, vorher gab es keine Probleme.
Hier ein Verbindungsversuch bei der Authentifizierung per Passwort (IP-Adresse, Benutzername anonymisiert):
$ ssh -vvv [email protected]
OpenSSH_8.1p1, OpenSSL 1.1.1d 10 Sep 2019
debug1: Reading configuration data /usr/local/etc/ssh/ssh_config
debug2: resolve_canonicalize: hostname 1.2.3.4 is address
debug2: ssh_connect_direct
debug1: Connecting to 1.2.3.4 [1.2.3.4] port 22.
debug1: Connection established.
debug1: identity file /Users/username/.ssh/id_rsa type -1
debug1: identity file /Users/username/.ssh/id_rsa-cert type -1
debug1: identity file /Users/username/.ssh/id_dsa type -1
debug1: identity file /Users/username/.ssh/id_dsa-cert type -1
debug1: identity file /Users/username/.ssh/id_ecdsa type -1
debug1: identity file /Users/username/.ssh/id_ecdsa-cert type -1
debug1: identity file /Users/username/.ssh/id_ed25519 type -1
debug1: identity file /Users/username/.ssh/id_ed25519-cert type -1
debug1: identity file /Users/username/.ssh/id_xmss type -1
debug1: identity file /Users/username/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.8
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.8 pat OpenSSH_7.0*,OpenSSH_7.1*,OpenSSH_7.2*,OpenSSH_7.3*,OpenSSH_7.4*,OpenSSH_7.5*,OpenSSH_7.6*,OpenSSH_7.7* compat 0x04000002
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to 1.2.3.4:22 as 'user'
debug3: hostkeys_foreach: reading file "/Users/username/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/username/.ssh/known_hosts:2
debug3: load_hostkeys: loaded 1 keys from 1.2.3.4
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],[email protected],[email protected],ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected],zlib
debug2: compression stoc: none,[email protected],zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1
debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:aTTwsnW7RYumH3f5rR0UqAsvZM5F2tgP1XQY33CZhTQ
debug3: hostkeys_foreach: reading file "/Users/username/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/username/.ssh/known_hosts:2
debug3: load_hostkeys: loaded 1 keys from 1.2.3.4
debug1: Host '1.2.3.4' is known and matches the ECDSA host key.
debug1: Found key in /Users/username/.ssh/known_hosts:2
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /Users/username/.ssh/id_rsa
debug1: Will attempt key: /Users/username/.ssh/id_dsa
debug1: Will attempt key: /Users/username/.ssh/id_ecdsa
debug1: Will attempt key: /Users/username/.ssh/id_ed25519
debug1: Will attempt key: /Users/username/.ssh/id_xmss
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
ssh_dispatch_run_fatal: Connection to 1.2.3.4 port 22: Operation timed out
In den Protokollen auf den Servern wird nichts angezeigt.
Antwort1
Diese Probleme werden normalerweise durch eine MTU-Nichtübereinstimmung verursacht.