My VM didn't have ssh server on it.

yes I add it in the dashboard and in command line, but even without icmp rules I can ping my VM. Maybe there is a problem of settings, I don't know.

I create the keypair, add it to the VM and try to ssh but it failed and it didn't talk about rsa key. I go to the VM and the ~/.ssh/authorized_keys is the same as mine. I try to telnet but it failed too. I try different port but nothing better.

Thank you very much it was all my fault...

There was a ssh client but no ssh server

Sorry I write it too quickly. I manage to create a VM with OpenStack. I add the rules for ping and ssh on OpenStack. There is a client SSH on my VM. But the ping is ok but not the SSH. I don't have any clue where is the problem, I can send you the nova.conf or all my config s network... I try with or without RSA key =/

I try this too :

killall dnsmasq

service nova-network restart

Can you help me ?

it is this one : test@one-PC:/usr/lib/ltp$ ssh -vvvv 172.16.0.3 OpenSSH_6.0p1 Debian-3ubuntu1, OpenSSL 1.0.1c 10 May 2012 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to 172.16.0.3 [172.16.0.3] port 22. debug1: connect to address 172.16.0.3 port 22: Connection refused ssh: connect to host 172.16.0.3 port 22: Connection refused