I am trying to set up a reverse ssh tunnel between a local machine behind a router and a machine on the Internet, so that the Internet machine can tunnel back and mount a disk on the local machine.
On the local machine, I type
/usr/bin/ssh -N -f -R *:2222:127.0.0.1:2222 root#ip_of_remote_machine
This causes the remote machine to listen on port 2222. But when I try to mount the sshfs disk on the remote machine, I get "connection refused" on the local machine. Interestingly, port 2222 doesn't show up on the local machine as being bound. However, I'm definitely talking to ssh on the local machine since it complains
debug1: channel 0: connection failed: Connection refused
I have GatewayPort set to Yes on both machines. I also have AllowTcpForwarding yes on both machines as well.
First, the line needs to be
/usr/bin/ssh -N -f -R *:2222:127.0.0.1:22 root#ip_of_remote_machine
Where port 22 represents the ssh server of the local machine.
Second, since I am using sshfs, the following line needs to be in its sshd_config
Subsystem sftp /usr/lib64/misc/sftp-server
Related
I have a google compute running CentOS 7, and I wrote up a quick test to try and communicate with it over port 9000 (from my home PC) - but I'm unexpectedly getting network errors.
This happens both with my test script (which attempts to send a payload) and even with plink.exe (which I'm just using to check the port availability).
>plink.exe -v -raw -P 9000 <external_IP>
Connecting to <external_IP> port 9000
Failed to connect to <external_IP>: Network error: Connection refused
Network error: Connection refused
FATAL ERROR: Network error: Connection refused
I've added my external IP to googles firewall (https://console.cloud.google.com/networking/firewalls) and set to allow ingress traffic over port 9000 (it's the lowest priority, at 1000)
I also updated firewalld in CentOS to allow TCP traffic over the port:
Redirecting to /bin/systemctl start firewalld.service
[foo#bar ~]$ sudo firewall-cmd --zone=public --add-port=9000/tcp --permanent
success
[foo#bar ~]$ sudo firewall-cmd --reload
success
I've confirmed my listener is running on port 9000
[foo#bar ~]$ netstat -npae | grep 9000
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
tcp 0 0 127.0.0.1:9000 0.0.0.0:* LISTEN 1000 18381 1201/python3
By default, CentOS 7 doesn't use iptables (just to be sure, I confirmed it wasn't running)
Am I missing something?
NOTE: Actual external IP replaced with <external_IP> placeholder
Update:
If I nmap my listener over port 9000 from the CentOS 7 compute instance over a local IP, like 127.0.0.1 I get some results. Interestingly, if I make the same nmap call over the servers external IP -- nadda. So this has to be a firewall, right?
external call
[foo#bar~]$ nmap <external_IP> -Pn
Starting Nmap 6.40 ( http://nmap.org ) at 2020-05-25 00:33 UTC
Nmap scan report for <external_IP>.bc.googleusercontent.com (<external_IP>)
Host is up (0.00043s latency).
Not shown: 998 filtered ports
PORT STATE SERVICE
22/tcp open ssh
3389/tcp closed ms-wbt-server
Nmap done: 1 IP address (1 host up) scanned in 4.87 seconds
Internal Call
[foo#bar~]$ nmap 127.0.0.1 -Pn
Starting Nmap 6.40 ( http://nmap.org ) at 2020-05-25 04:36 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up (0.010s latency).
Not shown: 997 closed ports
PORT STATE SERVICE
22/tcp open ssh
25/tcp open smtp
9000/tcp open cslistener
Nmap done: 1 IP address (1 host up) scanned in 0.10 seconds
In this case software running on the backend VM must be listening any IP (0.0.0.0 or ::), your's is listening to "127.0.0.1:9000" and it should be "0.0.0.0:9000".
The way to fix that it's to change the service config to listen to 0.0.0.0 instead of 127.0.0.1 .
Cheers.
I have a jetty server running under port 8080 on VM. VM in its turn runs on remote server under port 10000. Is it legit to address it as http://someremote.org:10000:8080/request? Or should I use SSH somehow?
What I was looking for is called ssh tunneling. You make a tunnel from your port to remote's machine port like that:
ssh -p 10000 -L 18080:localhost:8080 user#remote.host.org
18080 here is port, that you use on your local machine in order to get to remote's 8080 port.
I have docker host in a virtual machine.
the host is boot2docker 1.10-rc1.
and a container from a centOS 7.2 image.
I tried to run some application inside the container.
I started the two application and check the network status:
[root#564f3e59142b logs]# netstat -lnput
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:41656 0.0.0.0:* LISTEN 11995/BmtMDProvider
tcp6 0 0 :::44027 :::* LISTEN 4405/java
both application provides some HTTP service.
when I curl both applications (inside the same container) :
the response of java is OK
[root#564f3e59142b logs]# curl 127.0.0.1:44027
curl: (52) Empty reply from server
but on BmtMDProvider I got "connection reset by peer" instantly. This is a HTTP service url and it shouldn't return a "connection reset".
[root#564f3e59142b logs]# curl 127.0.0.1:41656
curl: (56) Recv failure: Connection reset by peer
the BmtMDProvider is some application from third party (I can't modify it) and works normally on a "real" machine.
Could I have some suggestion ,guide or diagnostic steps to find out where the "connection reset" comes from? Thanks.
Edit:
BmtMDProvider is a process spawned by java and it have a random port. the may be multiple instances of BmtMDProvider. java access BmtMDProvider by http (they are in same docker container and java got "connection reset", the same as curl)
Try running your container with IPV4 ports, meaning if you are currently running using
$ docker run -p 41656:41656 BmtMDProvider
run it as
$ docker run -p 127.0.0.1:41656:41656 BmtMDProvider
I am using the latest version of boot2docker version 1.3.2, 495c19a on a windows 7 (SP1) 64 bit machine.
My docker container is running a celery process which attempts to connect to a rabbitMQ service running on the same machine that boot2docker is running on.
The Celery process running within the docker container cannot connect to RabbitMQ and reports the following :
[2014-12-02 10:28:41,141: ERROR/MainProcess] consumer: Cannot connect
to amqp:// guest:**#127.0.0.1:5672//: [Errno 111] Connection refused.
Trying again in 2.00 seconds...
I have reason to believe this is a network related issue, associated with routing from the container, to the VirtualBox host, and from the host to the RabbitMQ service running on the local machine; I do not know how to configure this and I was wondering if anyone can advise me how to proceed?
I tried setting up port 5672 in port forwarding but it didn't work (but I believe this is for incoming traffic to the VM, like boot2docker ssh).
I am running the container as docker run -i -t tagname
I am not specifying a host with -h when I run the container.
I'm sorry if this question appears rather clueless or if the answer appears obvious ... I appreciate any help!
Some additional information :
The routing table of the host VM is what boot2docker configured during installation as follows :
docker0 IP Address is 172.17.42.1
eth0 IP Address is 10.0.2.15
eth1 IP Address is 192.168.59.103
eth0 is attached to NAT (Adapter 1) in the VirtualBox VM network configuration.
Adapter 1 has port forwarding setup for ssh; default setting of host IP 127.0.0.1, host port 2022, guest port 22.
eth1 is attached to Host-only adapter (Adapter 2).
Both adapters are set to promiscuous mode (allow all).
The IP Address of the docker container is 172.17.0.33.
[2014-12-02 10:28:41,141: ERROR/MainProcess] consumer: Cannot connect to amqp:// guest:**#127.0.0.1:5672//: [Errno 111] Connection refused. Trying again in 2.00 seconds...
127.0.0.1 is a special IP address that means "me", and inside the container it means "me the container", so this is why it is not connecting to the outer host. So the first thing to do is change the IP address where you are trying to connect to Rabbit to that of the outer host where it is running.
Then you probably have to do something about routing, but let's take one step at a time.
as your RabbitMQ server is running on your Windows host, you need to tell your container that it should talk to that IP - which would probably be 192.168.59.3
most importantly, your container's 127.0.0.1 is only a loopback device to that container's services - not even the boot2docker vm's ports.
You could set up an ambassador container that has --expose=80 and uses something like socat to forward all traffic from that container to your host (see svendowideit/ambassador). Then you'd --link that ambassador container to your current image
but personally, I'd avoid that initially, and just configure your containerised app to talk to the real host's IP
You have to specifc explicitely ports for port redirection separately for boot2docker and docker.
Please try this:
c:\>boot2docker init
c:\>boot2docker up
c:\>boot2docker ssh -L 0.0.0.0:5672:localhost:5672
docker#boot2docker:~$ docker run -it -p 5672:5672 tagname
I have a webapplication in Asp.net connecting to a separate database-server running CentOS with PostgreSQL. This setup works fine.
To increase performance on the database-server I'm trying to install and confgure PgPool-II for pooling database-connections on the CentOS server.
After the configuration I can connect to PostgreSQL with the pgpool configured port from the CentOS command line, so I assume pgpool is up and running.
When I try to connect from my webapplication to the database-server with my new pgpool port I get the following NpgdslException in the eventlog:
Failed to establish a connection to '[ip-address of db-server]'
Some configuration files:
pgpool.conf:
listen_address = '*'
port = 6432
pcp_port = 9898
enable_pool_hba = true
socket_dir = '/tmp'
pcp_socket_dir = '/tmp'
backend_hostname = ''
backend_port = 5432
num_init_children = 50
max_pool = 4
connection_life_time = 120
client_idle_limit = 0
debug_level = 0
pool_hba.conf:
# TYPE DATABASE USER CIDR-ADDRESS METHOD
# "local" is for Unix domain socket connections only
local all all trust
# IPv4 local connections:
host all all 127.0.0.1/32 trust
# Network access
host all all 192.168.0.0/24 md5
I have all the ports open in my CentOS firewall configured in /etc/sysconfig/iptables.
So when I'm connecting to port 5432 in my webapplication everything is fine, but when I change the port to 6432, the port for pgpool) then I get the mentioned exception.
Can anybody help me?
The first thing to do is to make sure that pgpool is running on the right port. This can be done easily using fuser:
fuser -n tcp 6432
If it doesn't return anything nothing is listening on your port. In that case make sure pgpool is running:
ps -A | grep pgpool
If this only shows your grep, then your pgpool has not been started. Please refer to your rpm information for information on how to start it. This may involve chkconfig and system