[Fiware-creatifi-coaching] [CreatiFI Barcelona Hub] unable to access our machines VIA SSH

[Xavier Carol Rossell]

Hi,

Developer added more information to this issue.


This afternoon machines were accessible again, but after doing some
iptables operations, servers are unavailable again. This is what we've done:

1. We have one server, lb.alquimia.io, with a floating IP and a public
internal
2. We have a couple of backend servers with public internal
3. We pass on traffic to some ports on the frontend to the backend servers.
To simulate this behavior, we are redirecting some ssh traffic on the head
to the ssh on the backends.
4. This is what we do:

root at sf-appserver1:~# echo "1" > /proc/sys/net/ipv4/ip_forward
root at sf-appserver1:~# iptables -t nat -A PREROUTING -p tcp --dport 22022 -j
DNAT --to-destination 10.10.13.102:22
root at sf-appserver1:~# iptables -t nat -A PREROUTING -p tcp --dport 22023 -j
DNAT --to-destination 10.10.13.105:22
root at sf-appserver1:~# iptables -t nat -A POSTROUTING -j MASQUERADE

where 10.10.13.102 and 105 are the backends.

I have been able to work for five minutes on the servers, but then ssh
client has became unresponsive, and servers are NOT appearing again on the
cloud.lab webpage. In fact, NOTHING is being displayed on the cloud.lab
portal: no images, no floating IPs, no keypairs, no security groups.

I would say that there is a link between the 'iptables' commands and the
connectivity problems, but I cannot even imagine what is the problem. I
have done this 'iptables' trick in other virtualized environments without
problems :/

Thanks,

i-




2015-02-26 9:21 GMT+01:00 Xavier Carol Rossell <xavier.carol at i2cat.net>:

> Hello,
>
> We are experiencing difficulties in accessing our machines via SSH.
> It is returning a time out "no route to host" error. We tried accessing
> from three different computers using different connections.
>
> We checked them in FiwareLab interface and they are there, running.
> However, the interface itself took some time to display the machines
> (something that didn't happen before).
>
> Regards.
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.fiware.org/private/fiware-creatifi-coaching/attachments/20150227/39e5c6d4/attachment.html>