Telnet / Security Groups - windows

I'm in the middle of installing and configuring an XMPP server, using ejabberd on Windows server 2012, running on an EC2 box.
I have opened port 5222 within windows firewall, and added to the security group for the EC2 instance
Custom TCP Rule
TCP
5222
0.0.0.0/0
ejabberd_c2s
Custom TCP Rule
TCP
5222
::/0
ejabberd_c2s
My XMPP logins are not working, and so I've turned to telnet to try and debug - it sees that port 5222 is reporting as closed:
PS C:\WINDOWS\system32> telnet hostname.com 5222
Connecting To hostname.com...Could not open connection to the host, on port 5222: Connect failed
Any guidance or steps towards debugging would be appreciated!

The issue here was in ejabberd's default configuration of "::" as an IP to listen, which forced it to listen only to IPv6.
By updating the ejabbed config to
port: 5222
ip: "0.0.0.0"
module: ejabberd_c2s
I was able to connect via telnet, and able to access the server using XMPP.

Related

I can't connect a webpage on my ec2

I am building simple webpage.
I could run on my local host.
I made ec2 instance, I opened ports 22, 8000.
I could connect with ssh and run server for webpage,
but I get this error
this is my github address that contain the code.
enter link description herehttps://github.com/MoreNiceJay/django2
In your security group rules, open port 80
This is the standard port for http traffic
Other things to check: login to the host with ssh and use netstat |grep LISTEN to see if there is a process listening on port 80

Able to open TCP port but not listening

Using Add rule in windows firewall, I was able to open TCP port 15537. When i am trying to executing command netstat -ano on terminal windows, this port is not listed. I tried to execute telnet command on terminal window (e.g. telnet IP port) but getting
Connecting To localhost...Could not open connection to the host, on port 15537: Connect failed
Then I downloaded PortQry application and execute it from different machine, this machine is also in the same network, the result I received was
"Not Listening".
I already spent more than 2 days and asked internal group but could not find solution.
Note: both machines are having Windows 10 OS.
No solution is needed as no problem is indicated in the question. You have opened a TCP port successfully. You have not made any attempt to cause anything to listen to that TCP port.
It's not clear what results you expected, but you got the results that you should have expected. Nothing is wrong. The port is open because you opened it. Nothing is listening on that port because you didn't set anything to listen on that port.
There may be some forwarding rules? Since the purpose of access is not on the local machine, the netstat command cannot see the port on listening, but it can see the next action based on this port, usually to do some forwarding
I am not very familiar with windows firewall configuration, but I know that if there is a forwarding rule in linux, like
-p tcp -m tcp --dport 8080 -j {other forwading chain}
we can not see 8080 listening on this host (netstat -tunpl), but telnet host:8080 may see connected
Use nmap instead of netstat for detecting opening port
nmap -p your_port_number your_local_ip
Run service on that port
For eg- In my case,in order to open port,I use
"service ssh start" or "service apache2 start "and it's open port 22 and 80 for connection respectively in my linux machine.
On using nmap in my lan network both ports opened.
Hope it help

Vagrant port fowarding on macOS?

I'm running postgresql on a Vagrant centos 7.2 box on macOS. I have confirmed postgres is up and running on the Vagrant box on port 5432 by connecting to it using psql on the box itself. I am attempting to forward port 5432 on the Vagrant box to port 10001 on my host machine as follows:
config.vm.define "acc_db" do | acc_db |
acc_db.vm.box = "bento/centos-7.2"
acc_db.vm.hostname = "acc.db"
acc_db.vm.network :forwarded_port, guest: 5432, host: 10001
acc_db.vm.provision "shell",
inline: "yum upgrade -y -q --nogpgcheck"
acc_db.vm.provision "shell",
path: "install_postgres.sh"
I have altered my pg_hba.conf to bind to all ip addresses and allow password authentication, as below:
# TYPE DATABASE USER ADDRESS METHOD
# "local" is for Unix domain socket connections only
local all all peer
# IPv4 local connections:
host all all 0.0.0.0/0 md5
# IPv6 local connections:
host all all ::1/128 ident
I have turned off the firewall but I am still unable to connect to postgres on port 10001 on the host machine:
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.10001"?
How do I fix this so that port forwarding works?
I have seen https://gielberkers.com/fixing-vagrant-port-forwarding-osx-yosemite/ but haven't tried it as it involves touching files I'm unfamiliar with. Is it the correct approach? It looks like you have to explicitly allow every port you want to forward via Vagrant.
...connections on Unix domain socket "/tmp/.s.PGSQL.10001" means that you are not attempting a TCP/IP connection, so port forwarding cannot happen.
By default, psql use Unix domain sockets on unix-like OSes.
Use the -h option of psql to specify a host, presumably 127.0.0.1 if using IPv4.
Additionally, the PostgreSQL server must listen to the network interface to which the connection will be routed. By default, it listens only to localhost for security reasons.
Setting listen_addresses='*' in postgresql.conf makes it listen on all existing interfaces.

Can't connect to public IP for EC2 instance

I have an EC2 instance which is running with the following security groups:
HTTP - TCP - 80 - 0.0.0.0/0
Custom UDP Rule - UDP - 1194 - 0.0.0.0/0
SSH - TCP - 22 - 0.0.0.0/0
Custom TCP Rule - TCP - 943 - 0.0.0.0/0
HTTPS - TCP - 443 - 0.0.0.0/0
However, when I try to access http://{PUBLIC_IP} or https://{PUBLIC_IP} in the browser, I get a "{IP} refused to connect" error. I'm new to AWS. Am I missing something here? What should I do to debug?
One way to debug this particular class of problem is to use netcat in order to determine where the problem lies.
If you run netcat against port 80 on the public IP address of your instance and just get a hang (no output at all), then most likely your security group isn't allowing traffic through. Here is an example from an EC2 instance that is in a security group that doesn't allow port 80 traffic inbound:
% nc -v 55.35.300.45 80
<just hangs>
Whereas if the security group is changed to allow port 80, but the EC2 instance doesn't have any process listening on port 80, you'll get the following:
% nc -v 55.35.300.45 80
nc: connectx to 52.38.300.43 port 80 (tcp) failed: Connection refused
Given that your browser gave you a similar "connection refused", most likely the problem is that there is no web server running on your instance. You can verify this by ssh'ing into the instance and seeing if you can connect to port 80 there:
ssh ec2-user#55.35.300.45
% nc -v localhost 80
nc: connect to localhost port 80 (tcp) failed: Connection refused
If you get something like the above, you're definitely not running a webserver.
I'm not sure if it's too late to help but I was stuck with a similar issue with my test server
SG Inbound: ssh -> 22
HTTP -> 80
NACL: default allow/deny settings
but still couldn't ping to the server from my browser, then I realize there's nothing running on the server that can serve the request, and I started httpd server (webserver) and it worked.
sudo yum -y install httpd
sudo service httpd start
this way you can test the connectivity if you are playing with SGs and NACLs and of course it's not the only way, just an example if you're figuring your System N/W out.
Have you installed webserver(ngingx/apache) to serve your requests. If so please share your the config files. (So that it will help to troubleshoot)
I think the reason is probably that you did not set up a web server for your EC2 instance, because if you try to access http://{PUBLIC_IP} or https://{PUBLIC_IP}, you need to have a background server to serve the http request as #Niranj Rajasekaran said.
By the way, by simply pinging the {PUBLIC_IP}, you could see if your connection to your EC2 instance is normal or not.
In command prompt or terminal, type
ping {PUBLIC_IP}
In my case, the server was running but available on just 127.0.0.1 so it refused connections from external hosts. To see if this is your situation, you can run
netstat -an | grep <port number>
If it says 127.0.0.1:<port number> instead of 0.0.0.0:<port number>, you have this problem.
Usually there's a flag or an argument in your server code somewhere to set the host to 0.0.0.0:
app.run(host='0.0.0.0') # flask example
However, in my case, I had already set this so I thought that couldn't possibly be the issue, which is how I ended up on this thread, which asks more generally about the problem. Unfortunately, I was using docker, and had set 0.0.0.0 on the container but was mapping that explicitly to 127.0.0.1 on the host in the docker-compose port-mapping:
ports:
- "127.0.0.1:<port number>:<port number>"
Changing that line to remove the host IP specification fixed the problem upon re-deploy:
ports:
- "<port number>:<port number>"

How to open incoming port 50070 in firewall (google compute engine)

I have my Single node Hadoop installed on Google Compute Engine instance and i want to open port 50070 on that machine to access the hadoop dashboard. i configured in the firewall rule as tcp:50070 in compute engine networks. but still i am unable to access my port outside the network (ie . via internet). I tried nmap for the public ip of my GCE instance and i got a result which has only ssh port got opened all other ports are filtered .
Note: i am using debian 7.5 image
Make sure your daemon is listening on port 50070. If you have more than one networks in you project make sure the port is opened on the right network. You can run the following commands to check the information about your instance and network.
lsof -i
gcutil --project= getinstance
gcutil --project= listnetworks
gcutil --project= listfirewalls
gcutil --project= getfirewall
Check if IP/Port is allowed in iptables or not.
iptables -L
would show you all the records.
To allow port in iptables you can do the following:
sudo iptables -A INPUT -p tcp -m tcp --dport 50070 -j ACCEPT
sudo iptables-save -c
Short answer
In addition to configure the firewall rule at GCE web console make sure that your server is listening at 0.0.0.0 instead of 127.0.0.1
Long answer
In the context of servers, 0.0.0.0 means all IPv4 addresses on the local machine. If a host has two IP addresses, 192.168.1.1 and 10.1.2.1, and a server running on the host listens on 0.0.0.0, it will be reachable at both of those IPs - Source
In contrast 127.0.0.1 is the IP address used to stablish a connection to the same machine used by the user this address is usually referred as the localhost.
It's often used when you want a network-capable application to only serve clients on the same host. A process that is listening on 127.0.0.1 for connections will only receive local connections on that socket. - Source
Hence, if you try to stablish a connection to your server from internet and your server is listening at 127.0.0.1 at your GCE machine, then, from the server point of view a request has never been received and as a consequence Goocle Cloud Firewall will refuse the connection because there is no server listening at the opened port (in your case 50070).
I hope this answer helps to solve your problem. Best regards.

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