Xutho Posted February 25, 2023 Share Posted February 25, 2023 Hi folks, maybe you can give me a hint.. i´ve a strange issue with SSH. I´ve 2 Unraid Systems up and running Live-System and Backup System Backup System is connected via Wiregurad to my opnsense Router (successfully i have fully access to that machine) Last years i made backups with rsync to that Backup system on a daily basis. But somehow now rsync has connection problems rsync -avzse "ssh -i /root/.ssh/siteA-rsync-key" --bwlimit=50000 --delete /mnt/user/Backup/ [email protected]:/mnt/user/Data/Xutho-Unraid/Backup/ Connection closed by 10.6.0.3 port 22 rsync: connection unexpectedly closed (0 bytes received so far) [sender] rsync error: unexplained error (code 255) at io.c(231) [sender=3.2.7] as well if i try from my live-system to open a SSH connection root@Xutho-Unraid:~/.ssh# ssh [email protected] Connection closed by 10.6.0.3 port 22 root@Xutho-Unraid:~/.ssh# But i can see that try on my Backup-System: Feb 25 20:08:31 Xutho-Backup sshd[4935]: Connection from 192.168.178.100 port 58776 on 10.6.0.3 port 22 rdomain "" Feb 25 20:09:02 Xutho-Backup flash_backup: adding task: /usr/local/emhttp/plugins/dynamix.my.servers/scripts/UpdateFlashBackup update Feb 25 20:10:02 Xutho-Backup flash_backup: adding task: /usr/local/emhttp/plugins/dynamix.my.servers/scripts/UpdateFlashBackup update Feb 25 20:10:31 Xutho-Backup sshd[4935]: fatal: Timeout before authentication for 192.168.178.100 port 58776 Funny thing: all my clients on the same network as my Live-System can flawless connect via SSH to Backup-System except my Live-System...... Is there any kind of blacklist? Is maybe my Live-System kinda locked out? Quote Link to comment
JorgeB Posted February 26, 2023 Share Posted February 26, 2023 ssh -vvv might help see what the problem is. Quote Link to comment
Xutho Posted February 26, 2023 Author Share Posted February 26, 2023 21 minutes ago, JorgeB said: ssh -vvv might help see what the problem is. Hi Jorge it stucks at "debug1: expecting SSH2_MSG_KEX_ECDH_REPLY" and after ~30 sec´s the connection will be closed. root@Xutho-Unraid:~# ssh [email protected] -vvv OpenSSH_9.1p1, OpenSSL 1.1.1s 1 Nov 2022 debug1: Reading configuration data /root/.ssh/config debug1: Reading configuration data /etc/ssh/ssh_config debug2: resolve_canonicalize: hostname 10.6.0.3 is address debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/root/.ssh/known_hosts' debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/root/.ssh/known_hosts2' debug1: Authenticator provider $SSH_SK_PROVIDER did not resolve; disabling debug3: ssh_connect_direct: entering debug1: Connecting to 10.6.0.3 [10.6.0.3] port 22. debug3: set_sock_tos: set socket 3 IP_TOS 0x48 debug1: Connection established. debug1: identity file /root/.ssh/id_rsa type 0 debug1: identity file /root/.ssh/id_rsa-cert type -1 debug1: identity file /root/.ssh/id_ecdsa type -1 debug1: identity file /root/.ssh/id_ecdsa-cert type -1 debug1: identity file /root/.ssh/id_ecdsa_sk type -1 debug1: identity file /root/.ssh/id_ecdsa_sk-cert type -1 debug1: identity file /root/.ssh/id_ed25519 type -1 debug1: identity file /root/.ssh/id_ed25519-cert type -1 debug1: identity file /root/.ssh/id_ed25519_sk type -1 debug1: identity file /root/.ssh/id_ed25519_sk-cert type -1 debug1: identity file /root/.ssh/id_xmss type -1 debug1: identity file /root/.ssh/id_xmss-cert type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: identity file /root/.ssh/id_dsa-cert type -1 debug1: Local version string SSH-2.0-OpenSSH_9.1 debug1: Remote protocol version 2.0, remote software version OpenSSH_9.1 debug1: compat_banner: match: OpenSSH_9.1 pat OpenSSH* compat 0x04000000 debug2: fd 3 setting O_NONBLOCK debug1: Authenticating to 10.6.0.3:22 as 'root' debug3: record_hostkey: found key type ECDSA in file /root/.ssh/known_hosts:1 debug3: load_hostkeys_file: loaded 1 keys from 10.6.0.3 debug1: load_hostkeys: fopen /root/.ssh/known_hosts2: No such file or directory debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],ecdsa-sha2-nistp256 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: [email protected],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,ext-info-c debug2: host key algorithms: [email protected],ecdsa-sha2-nistp256,[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],rsa-sha2-512,rsa-sha2-256 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],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 debug2: host key algorithms: 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 Connection closed by 10.6.0.3 port 22 root@Xutho-Unraid:~# Quote Link to comment
Solution Xutho Posted February 26, 2023 Author Solution Share Posted February 26, 2023 (edited) I´ve managed to get it working again.... Somehow Wireguard didn´t run correctly on that Backup-Machine. So i deleted all of the config and created a whole new profile in Wireguard for that machine (but same IP) After i established my connection SSH was working fine.... strange behaviour that only SSH was kinde screwed up but nevermind ... it works again @JorgeB thanks for that quick reply i´ve learned again something new for future "ssh root@ip -vvv" never saw that paramenter for debugging Edit: I´ve found the exact issue! There seems to be a dependency with my MTU Value - I set it to 1440 and the issue was reproducable - after setting it back to AUTO the issue with SSH from Unraid-Server was gone. Hopefully this helps someone in future Edited March 2, 2023 by Xutho 1 Quote Link to comment
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