Unable to connect to mongo on remote server

问题

I have installed mongo on machine1(Ubuntu 14.04.3 LTS server) in my local network. I have also opened the port 27017 as mentioned in this guide using following commands:

sudo iptables -A INPUT -p tcp --destination-port 27017 -m state --state NEW,ESTABLISHED -j ACCEPT
sudo iptables -A OUTPUT  -p tcp --source-port 27017 -m state --state ESTABLISHED -j ACCEPT

Current rules are (iptables -L):

Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:27017 state NEW,ESTABLISHED

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

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

But I am not able to connect to this port from machine2 (in the same network):

$ mongo --host 192.168.0.108
MongoDB shell version: 3.0.4
connecting to: 192.168.0.108:27017/test
2016-01-23T18:02:14.848+0530 W NETWORK  Failed to connect to 192.168.0.108:27017, reason: errno:61 Connection refused
2016-01-23T18:02:14.850+0530 E QUERY    Error: couldn't connect to server 192.168.0.108:27017 (192.168.0.108), connection attempt failed
    at connect (src/mongo/shell/mongo.js:181:14)
    at (connect):1:6 at src/mongo/shell/mongo.js:181
exception: connect failed

I also tried checking if port is opened or not:

$ nc -v 192.168.0.108 27017
nc: connectx to 192.168.0.108 port 27017 (tcp) failed: Connection refused

I am not sure what I am missing. Must be some silly mistake as I am setting up mongo for the first time. Pls help.

Update (for the doubts raised in current answers)

Yeah its running. I am able to connect to mongo form the same machine but not from the other machine. The daemon is running: $ service mongod status mongod start/running, process 31205 and the port is 27017 $ sudo netstat -tulpn |grep 27017 tcp 0 0 127.0.0.1:27017 0.0.0.0:* LISTEN 31205/mongod
I changed the bind_ip to 0.0.0.0 and restarted mongo. Still the same error is coming.

Mongo logs:

$ cat /var/log/mongodb/mongod.log
2016-01-23T16:28:13.155+0530 I CONTROL  [initandlisten] MongoDB starting : pid=31205 port=27017 dbpath=/var/lib/mongodb 64-bit host=dexter
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten] db version v3.2.1
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten] git version: a14d55980c2cdc565d4704a7e3ad37e4e535c1b2
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten] OpenSSL version: OpenSSL 1.0.1f 6 Jan 2014
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten] allocator: tcmalloc
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten] modules: none
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten] build environment:
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten]     distmod: ubuntu1404
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten]     distarch: x86_64
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten]     target_arch: x86_64
2016-01-23T16:28:13.156+0530 I CONTROL  [initandlisten] options: { config: "/etc/mongod.conf", net: { bindIp: "127.0.0.1", port: 27017 }, storage: { dbPath: "/var/lib/mongodb", journal: { enabled: true } }, systemLog: { destination: "file", logAppend: true, path: "/var/log/mongodb/mongod.log" } }
2016-01-23T16:28:13.173+0530 I STORAGE  [initandlisten] wiredtiger_open config: create,cache_size=1G,session_max=20000,eviction=(threads_max=4),config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000),checkpoint=(wait=60,log_size=2GB),statistics_log=(wait=0),
2016-01-23T16:28:14.444+0530 I CONTROL  [initandlisten]
2016-01-23T16:28:14.444+0530 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2016-01-23T16:28:14.444+0530 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2016-01-23T16:28:14.444+0530 I CONTROL  [initandlisten]
2016-01-23T16:28:14.444+0530 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2016-01-23T16:28:14.444+0530 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2016-01-23T16:28:14.444+0530 I CONTROL  [initandlisten]
2016-01-23T16:28:14.444+0530 I FTDC     [initandlisten] Initializing full-time diagnostic data capture with directory '/var/lib/mongodb/diagnostic.data'
2016-01-23T16:28:14.444+0530 I NETWORK  [HostnameCanonicalizationWorker] Starting hostname canonicalization worker
2016-01-23T16:28:14.949+0530 I NETWORK  [initandlisten] waiting for connections on port 27017
2016-01-23T16:38:37.046+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:37032 #1 (1 connection now open)
2016-01-23T16:39:31.447+0530 I NETWORK  [conn1] end connection 127.0.0.1:37032 (0 connections now open)
2016-01-23T16:49:24.240+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:37033 #2 (1 connection now open)
2016-01-23T16:49:38.249+0530 I NETWORK  [conn2] end connection 127.0.0.1:37033 (0 connections now open)
2016-01-23T16:51:51.707+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:37034 #3 (1 connection now open)
2016-01-23T16:51:55.785+0530 I NETWORK  [conn3] end connection 127.0.0.1:37034 (0 connections now open)
2016-01-23T17:32:15.546+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:37036 #4 (1 connection now open)
2016-01-23T17:32:21.180+0530 I NETWORK  [conn4] end connection 127.0.0.1:37036 (0 connections now open)
2016-01-23T18:11:57.885+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:37037 #5 (1 connection now open)
2016-01-23T18:29:55.365+0530 I NETWORK  [conn5] end connection 127.0.0.1:37037 (0 connections now open)

回答1:

make sure that mongodb daemon is running, and listening on 0.0.0.0, but not 127.0.0.1 port

for example, for my local mongodb, it has this config:

[vodolaz095@steel ~]$ cat /etc/mongod.conf 
##
### Basic Defaults
##

# Comma separated list of ip addresses to listen on (all local ips by default)
bind_ip = 127.0.0.1

# Specify port number (27017 by default)
#port = 27017

for mongodb server to listen for remote connections, you can change

# Comma separated list of ip addresses to listen on (all local ips by default)
bind_ip = 0.0.0.0

回答2:

With mongoDB server version 3.6.4, Ubuntu 16.4.4 I solved this by setting the net section in /etc/mongod.conf like this:

net:
  port: 27017
  bindIpAll: true
#  bindIp: 127.0.0.1

回答3:

The issue was bindIp didn't change. There was some issue in restarting mongo from my side.

The habit should be to verify if the bindIp actually changed or not. (using sudo netstat -tulpn | grep 27017)

回答4:

Make sure you have a daemon running on your machine1 which listen to port 27017. We were getting the same error and found that daemon was not running.