Unable to SSH into Vagrant guest

Question

Until recently I was able to SSH into my Vagrant machine without any problems. Now however:

$ ssh -vvv vagrant@127.0.0.1 -p 2222 OpenSSH_7.2p2 Ubuntu-4ubuntu2.1, OpenSSL 1.0.2g 1 Mar 2016 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug2: resolving "127.0.0.1" port 2222 debug2: ssh_connect_direct: needpriv 0 debug1: Connecting to 127.0.0.1 [127.0.0.1] port 2222. debug1: Connection established. debug1: key_load_public: No such file or directory debug1: identity file /home/user1/.ssh/id_rsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/user1/.ssh/id_rsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/user1/.ssh/id_dsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/user1/.ssh/id_dsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/user1/.ssh/id_ecdsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/user1/.ssh/id_ecdsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/user1/.ssh/id_ed25519 type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/user1/.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-4ubuntu2.1 ssh_exchange_identification: read: Connection reset by peer

I checked /etc/hosts.allow and /etc/hosts.deny in the guest. Nothing there. I'm almost sure this has something to do with someone rewriting the contents of /etc/resolv.conf . The contents are now: nameserver 8.8.8.8 nameserver 8.8.4.4 The network seems to be fine on the host where I can ping google.com, but not on the guest, where I can't. But SSH to the Vagrant machine is no longer working. Any ideas?

Answer 1

The answer is not at all what I expected. In VirtualBox Settings > Network > Adapter 1 the Cable Connected option was disabled. After enabling it everything went back to normal.