Suppose if my ip address is : 192.65.35.12. In this machine I'm running node server. I can access the webpages by using this url: http://localhost:3000/ in the same machine.
But, if I'm trying to access the node server from a remote machine having the ip 192.65.35.11. It does not work. I used the below url to access the url from the remote machine:
http://192.65.35.12:3000/
I'm facing network connectivity issues.
Do, I need to change any settings in node.js for remote access.
Then, how can I access the node server from the remote machine.
Use this IP 0.0.0.0 to open your app on all interfaces provided by your computer.
On linux server you need to open port for outside client to reach it.
$ sudo iptables -I INPUT -p tcp -m tcp --dport 3000 -j ACCEPT
$ sudo service iptables save
$ sudo service iptables restart
Then start your server
Related
I was requested to create a Web Server with an API in it to test firewall rule we are planning to implement soon. I am quite new with all this network stuff, so I'm a bit lost on it.
I need to call this API from another machine. The JsonServer is using my port 3000, when I request my API through Postman, using https://localhost:3000/posts, my JSON file is returned normally, however when I change the localhost, to my IP, my connection is being refused. I decided to install a WebServer, to test it and I could access the default Apache page from my others machines. I opened the port 3000 on my server, but I couldn't. The WebServer is working with my IP as well. It seems to be something with my port 3000, and I a not sure about how to fix that.
I executed the command:
sudo lsof -i -P -n | grep 3000
And this was my output
node 29472 user 22u IPv4 254348 0t0 TCP 127.0.0.1:3000 (LISTEN)
Any ideas how can I access my API from another machine?
Using Docker 1.12.1, I face a strange behaviour trying to access a host port created with ssh -R.
Basically I try to access a service running on port 12345 on my local machine from a docker container running on a server.
I opened a ssh connection with ssh -R *:12345:localhost:12345 user#server to open a port 12345 on server that forwards to port 12345 on my local machine.
Now when I try curl https://172.17.42.1:12345 inside the container (172.17.42.1 is the IP to access the docker host from the docker container) I get :
root#f6873fe1109b:/# curl https://172.17.42.1:12345
curl: (7) Failed to connect to 172.17.42.1 port 12345: Connection refused
But on server the command curl http://localhost:12345 succeeds (eg. no Connection refused)
server$ curl http://localhost:12345
curl: (52) Empty reply from server
I don't really understand how the port binding done with ssh differs from a test with nc on server (it works) :
# on server
nc -l -p 12345
# inside a container
root#f6873fe1109b:/# curl http://172.17.42.1:12345
curl: (52) Empty reply from server
NB: the container was started with docker run -it --rm maven:3-jdk-8 bash.
What can I do to allow my container to access the host port corresponding to a ssh binding ?
From man ssh:
-R [...]
... Specifying a remote bind_address will only succeed if the server's GatewayPorts option is enabled
And man sshd_config:
GatewayPorts
Specifies whether remote hosts are allowed to connect to ports forwarded for the client. By default, sshd(8) binds remote port forwardings to the loopback address. This prevents other remote hosts from connecting to forwarded ports. GatewayPorts can be used to specify that sshd should allow remote port forwardings to bind to non-loopback addresses, thus allowing other hosts to connect. The argument may be “no” to force remote port forwardings to be available to the local host only, “yes” to force remote port forwardings to bind to the wildcard address, or “clientspecified” to allow the client to select the address to which the forwarding is bound. The default is “no”.
This means that a default sshd server installation only allows to create forwards that bind to the local interface. If you want to allow forwards to other interfaces then loopback, you need to set the GatewayPorts option to yes or clientspecified in your /etc/ssh/sshd_config
I try to access my node.js server running on Ubuntu. My PC is connected with TP-link router. Now, I want to access node services from other IP(not from my local host or local IPs). What can I do? I used following code.
Note: This server works fine and accessible from local IP but can't access from my public IP
http.listen(6000,"0.0.0.0",function(){
log.info("server started");
})
You have to use :-
iptables -A OUTPUT -p tcp --sport 8080 -j ACCEPT
for the outgoing rule (not dport). Apart from that, maybe there's an earlier rule that blocks the traffic? Try iptables -L.
Ubuntu have very good firewall and default system is not allow to external IP to response
In express and node js or any server like that
http.listen(6000,"0.0.0.0",function(){
log.info("server started");
})
It will work on your IP, localhost and public IP
but on external IP can't access it
first of all replace
localhost -> 0.0.0.0
when you want to run frontend and backend simultaneously
then it is better to use public IP directly instead of 0.0.0.0
If you are using ubuntu then we need to change in firewall settings using ufw
UFW is installed by default on Ubuntu. If it has been uninstalled for some reason, you can install it with apt-get:
sudo apt-get install ufw
then
sudo nano /etc/default/ufw
check this line and make it yes
IPV6=yes
save file using Ctrl-X to exit the file, then shift + y to save the changes that you made, then ENTER
At any time, you can check the status of UFW with this command:
sudo ufw status verbose
By default, UFW is disabled so you should see something like this:
Output:
Status: inactive
Not most important point
sudo ufw allow portNumber // here portNumber is port-number in integer
in your case
sudo ufw allow 6000
and allow
sudo ufw allow http
for more rules and firewall on ubuntu click here
I have created a debian wheezy virtual machine in google compute engine but I am unable to connect to it with vnc.
Here is what I have done
Installed gnome and the rebooted the VM
install tightvncserver and started it
I have tried to connect using the static ip that I've attached to the VM but I'm getting the error: "the connection was refused by the host computer".
I thought it was the firewall that was the issue so I disabled iptable using the following commands
$ sudo iptables-save > /root/firewall.rules
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
and I have created rules in google firewall to allow ports 0-65535 for tcp and udp but it still does not work.
Anyone knows how to do it?
Thanks in advance
By default, all incoming traffic from outside a network is blocked and no packet is allowed into an instance without an appropriate firewall rule. To allow incoming network traffic, you need to set up firewall rules to permit these connections:
start the VNC service
look at VNC server settings or netstat -nap to find out the listening port of vnc server
under Google Developer console -> Compute Engine -> Networks -> default -> Firewall rules
create a new rule and open appropriate ports for incoming vnc connections.
VNC uses by default port 5901. In the 'VNC server' field, specify the ip address and the port 5901.
Example: VNC ***Server: 123.123.123.123:5901
Encryption: let VNC Server choose***
Be aware that the free edition of VNC doesn't support encryption, it only encrypts your user name and password. One thing also to configure is /etc/sysconfig/vncservers file where you have to specify the user and the port that VNC server should listen to, and make sure it's not commented
Example:
VNCSERVERS="1:USERNAME"
VNCSERVERAR0GS[1]="-geometry 800x600 -listen tcp -5901"
I have a webservice running on a remote machine available to me through ssh tunneling. Therefore I will be able to access the webservice through http://[local machine ip]:8888. But the problem here is, My source code trying to access the webservice through the public ip (http://[remote server ip]:7777). So I need all the traffic originated from my local machine to the remote machine should be redirected to http://[local machine ip]:8888.
For eg http://[remote server ip]:7777 Redirected to http://[local machine ip]:8888
Please note: the ports are different and my OS is ubuntu 12.04
Try a rule like this:
iptables -t nat -A OUTPUT -p tcp -d [remote server ip] --dport 7777 \
-j DNAT --to-destination [local machine ip]:8888