Why Google Cloud Compute Engine instance gives ssh connection refused after restart?

Question

I stopped and restarted an ubuntu 14.04 Google Cloud Compute Engine instance, and now my ssh connection is refused with:

ssh: connect to host 146.148.114.98 port 22: Connection refused

This already happened a previous time, I thought there was a problem with the machine, I deleted it and recreated and it started working again. I don't want to be recreating instances every time. The ssh troubleshooting page of google cloud is quite messy. My firewall rules seem to be ok. Anyone has a solution for this?

NAME                    NETWORK  SRC_RANGES    RULES                         SRC_TAGS  TARGET_TAGS
default-allow-http      default  0.0.0.0/0     tcp:80                                  http-server
default-allow-https     default  0.0.0.0/0     tcp:443                                 https-server
default-allow-icmp      default  0.0.0.0/0     icmp
default-allow-internal  default  10.128.0.0/9  tcp:0-65535,udp:0-65535,icmp
default-allow-rdp       default  0.0.0.0/0     tcp:3389
default-allow-ssh       default  0.0.0.0/0     tcp:22

This is the output for: ps aux | grep ssh

root        29  0.0  0.4  55184  2860 ?        Ss   11:26   0:00 /usr/sbin/sshd -p 22 -o AuthorizedKeysCommand=/google/devshell/authorized_keys.sh -o Author
izedKeysCommandUser=root
root       183  0.0  0.9  82692  5940 ?        Ss   11:26   0:00 sshd: fbeshox [priv]                                                                       

fbeshox    218  0.0  0.7  82692  4424 ?        S    11:26   0:00 sshd: fbeshox@pts/0                                                                        

fbeshox    522  0.0  0.3  12728  2200 pts/1    S+   12:12   0:00 grep ssh

Here the verbose results of the ssh connetion attempt.

ssh -i .ssh/keyname [email protected] -vvv
OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
debug1: Reading configuration data /Users/xxxx/.ssh/config
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug1: /etc/ssh_config line 102: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 130.211.53.51 [130.211.53.51] port 22.
debug1: connect to address 130.211.53.51 port 22: Connection refused
ssh: connect to host 130.211.53.51 port 22: Connection refused

Answer 1

It is possible that sshguard, a security tool installed on Ubuntu by default, is interfering with your connection. Basically sshguard might have incorrectly decided that your IP address is 'attacking' your instance and blocked the IP.

If you can log in from a different location, such as the Web SSH provided by the Cloud Console, try using sudo iptables -S to see if there are any firewall rules on the instance (different than the GCE firewall) created by sshguard. If so try disabling sshguard or adding your IP address on the whitlelist (http://www.sshguard.net/docs/whitelist/).

Answer 2

I know this is an old question but today I had similar issue and the problem was very simple - IP of the instance is changed after restart - so I had to update ssh string accordingly