I'm having trouble using ssh to access a server that I recently set up with 16.04, but only from a specific computer (my laptop). When I run ssh -vvv -p sshPort user@host
, I get this output:
OpenSSH_7.2p2 Ubuntu-4, OpenSSL 1.0.2g-fips 1 Mar 2016
debug1: Reading configuration data /home/user/.ssh/config
debug1: /home/user/.ssh/config line 1: Applying options for *
debug1: /home/user/.ssh/config line 35: Applying options for host
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: resolving "host" port xxxx
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to host [xxx.xxx.xxx.xxx] port xxxx.
debug1: Connection established.
debug1: identity file /home/user/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /home/user/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/user/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/user/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/user/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/user/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/user/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/user/.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-4
ssh_exchange_identification: Connection closed by remote host
On the server side, /var/log/auth.log
just has the entry:
Apr 28 18:50:49 host sshd[2618]: Did not receive identification string from yyy.yyy.yyy.yyy
So far, I haven't been able to figure out why this is happening, and I'm open to suggestions. A few things I've ruled out:
Not port forwarding/firewall configuration issues: I'm able to log in to this host from a remote VPS, so access from the WAN is working properly. I can also ssh in from another host on the same LAN.
Not an issue with fail2ban/denyhosts: This is a new install that doesn't yet have auto-ban software configured. /etc/hosts.deny
and /etc/hosts.allow
are both empty. SSH config is the default that ships with 16.04.
Not the SSH agent: I can ssh into other hosts from my laptop with agent forwarding and from there SSH into the host I'm having trouble with.
I did recently install kvm and bridge-utils on the laptop. I've seen some mentions of bridge-utils possibly being an issue here, but I doubt it, since ssh works fine with other hosts.
Any help would be greatly appreciated!