Can't connect to remote mongodb with mongo shell

Question

I am attempting to connect to a remote mongodb service and cannot figure out how to get it to work. The remote mongod is running on an Ubuntu box. I am a very novice unix user, but I'm reasonably certain the problem is that I am not opening up the firewall probably with iptables , I've tried the commands in the mongodb docs and still no success.

mongodb.conf relevant rules

bind_ip = 0.0.0.0
port = 27017
auth = false

netstat -A

Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 *:28017                 *:*                     LISTEN
tcp        0      0 *:27017                 *:*                     LISTEN

iptables -L -n

target     prot opt source               destination
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:22
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:80
DROP       all  --  0.0.0.0/0            0.0.0.0/0
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:27017 state NEW,ESTABLISHED
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:28017 state NEW,ESTABLISHED

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp spt:27017 state ESTABLISHED

iptables commands executed as documented in mongodb docs at - http://docs.mongodb.org/manual/tutorial/configure-linux-iptables-firewall/#patterns

Here is what I've tried:

browser: http://xx.xx.xx.xx:27017/ no response.

browser: http://xx.xx.xx.xx:28017/ no response.

browser: http://www.hostname.com:27017/ no reponse.

browser: http://www.hostname.com:28017/ no response.

mongo.exe xx.xx.xx.xx:27017 (remotely) couldn't connect to server xx.xx.xx.xx

mongo xx.xx.xx.xx:27017 (from localhost) connects properly

mongo www.hostname.com:27017 (from localhost) connects properly

The fact that it connects properly over localhost on the server hosting the mongodb, even when I specify the IP address, makes me think it has to be a firewall issue. Any ideas?

Answer 1

iptables rules are read in exactly in the order as they appear. You now have DROP taking precedence over ACCEPT of your mongodb ports.

Shuffle the lines in your particular script that sets up iptables and flush and re-read them back in.

If you haven't saved your firewall yet, remove the DROP rule and re-add it again, it will shift it down the list and will also solve your issue.