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Questions tagged [port]

The tag has no usage guidance.

0
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1answer
18 views

How to open a port to specific IPs in iptables while using docker?

I have a postgreSQL database inside of Docker that I don't want to expose it to the host network as it causes all users to see the exposed database port. (For now I don't have a pfsense or anything ...
-1
votes
0answers
26 views

Opening ports on my computer to the internet [closed]

I want to run a server on my desktop, that is accessible from the internet. How should I do that? I've created a node server which runs at port 4522, but when I use a browser to access the server, ...
0
votes
0answers
18 views

VSFTPD refuses to list directory when PASV is enabled

I'm configuring VSFTPD on Ubuntu 18.04 and have followed all the guidelines. It's working OK for plain FTP (insecure), however as soon as I enable SSL/TLS and Passive mode, it connects, but I am ...
0
votes
0answers
21 views

Mapping Docker container UDP port to different host port causes only partial communication failure [migrated]

I have a game server running inside a Docker container that listens on UDP port 1111 (EXPOSE 1111/udp). When I publish this server on the same port on the host (-p 1111:1111/udp) everything works as ...
0
votes
2answers
65 views

When does `[::]` or `0.0.0.0` mean this network and when this host? [duplicate]

Tanenbaum's Computer Networks says The IP address 0.0.0.0, the lowest address, is used by hosts when they are being booted. It means ‘‘this network’’ or ‘‘this host.’’ [::] is IPv6 version of ...
-2
votes
1answer
29 views

Does `rpcinfo` list the port number of a RPC service?

$ rpcinfo program version netid address service owner 100000 4 tcp6 ::.0.111 portmapper superuser 100000 3 tcp6 ::.0.111 ...
1
vote
1answer
29 views

Why does postgresql server have a `localhost:57504` to `localhost:57504` UDP “connection”?

$ sudo netstat -ap | grep postg tcp 0 0 localhost:postgresql 0.0.0.0:* LISTEN 1567/postgres udp 0 0 localhost:57504 localhost:57504 ...
1
vote
1answer
43 views

Why is mysql server accepting nonlocal request, while postgresql server is not?

By default configurations, why is mysql server accepting nonlocal request, while postgresql server is not? $ nmap -p0-65535 192.168.1.97 Starting Nmap 7.60 ( https://nmap.org ) at 2019-03-20 14:34 ...
0
votes
0answers
34 views

Why can't `lsof` report some open port's information? [duplicate]

I am running this with the IP address of the same machine: $ nmap -p0-65535 192.168.1.198 Starting Nmap 7.60 ( https://nmap.org ) at 2019-03-20 10:13 EDT Nmap scan report for olive.fios-router.home (...
0
votes
0answers
17 views

writing data out to already opened port

I have a setup in which one unix program (s51 from a microcontroller simulation package) is a server tied to a specific port. Let's call the port 111. I also have setup a client on the same computer ...
2
votes
1answer
35 views

Red Hat Linux - port is in listening state but could not find process ID

I have this problem for my application, port is in listening state but process ID is not showing up. Used below commands. This is cloud AWS server Red Hat Linux. $ netstat -tulpn tcp 0 ...
0
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0answers
16 views

send hex as characters to output to remote end

I'm doing a project for a microcontroller that involves sending and receiving special (non-printable character) data through its serial port. I found myself a simulator (ucsim) so I can test things ...
0
votes
1answer
30 views

Can't access SNMP stack on rasp pi through router from WAN

Background I am running the following On my laptop the very latest version of arch linux with all the latest updates. It is from this laptop that I am querying an SNMP stack on a rasp pi $ uname -...
0
votes
2answers
169 views

Linux's Internet domain socket, transport protocols (TCP/UDP)'s socket and port

I have been bothered for a long while by some confusions among internet domain socket provided by Linux, transport protocols (TCP/UDP)'s socket and transport protocols (TCP/UDP)'s port. ...
1
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0answers
60 views

Why there are 65535 ports [closed]

Wondering why they chose to have 16-bit (65535) ports. Why not just 256 or millions. I understand it's a power of 2, but not why it was this size. Wondering in what situations it would make sense to ...
0
votes
0answers
12 views

Can't connect to OpenLDAP

i have installed iRedMail with OpenLDAP managing the Mail Accounts. So far that works. Now I wan't to connect other applications to that LDAP and I'm trying to use a LDAP Explorer "LDAP Admin" for ...
2
votes
1answer
39 views

Is there a way to figure out what physical port a drive is being inserted into through linux?

Without knowing the order of which drives are being inserted and which ports they are being inserted (by human eye), is there a way to tell where they are being inserted using linux commands? I need ...
0
votes
1answer
41 views

Open port 4000 for Trader Workstation in Fedora

I have installed Trader WorkStation by Interactive Brokers. However, the program does not run, with assistance from support I found that the firewall is the problem. The servers (several primary and ...
0
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0answers
12 views

OpenVPN Gateway with Killswitch and Prerouting Ports

My Prerouting in UFW Doesnt work. I´m using an VPN Connection via tun0. Internet Connections via tun0 as a gateway works but not the Port Forwarding. im on debian Strech 9 UFW Before Rules. Only ...
0
votes
1answer
171 views

iptables priority

After deploying all kubernetes ressources I wanna open port 443. I added it to my whitelist table but it is still closed. Same already happened to me for port 80. After flushing all tables, deleting ...
-2
votes
2answers
71 views

How make a port appear open with an nmap scan

To avoid someone knowing which port are open on my machine, I thought it would useful to open all unused port so that the nmaper is unable to identify which port are really open. How make a port ...
0
votes
1answer
35 views

Networking: port listening but nc fails

I have set up a docker-compose stack on a server. One of its services is jaeger collector and is configured as follows: collector: image: jaegertracing/jaeger-collector:1.8 environment: ...
0
votes
1answer
30 views

One port is listening with an * and the other is listening with 127.0.0.1 and only the first is accepting remote connections

Please see the attached picture below, and then I will explain: So, I have Solr running which uses port 8983. And as you can see in the screen shot, it's listed as "TCP *:8983 (LISTEN)". And, it's ...
0
votes
2answers
73 views

port 1556 listening on tcp6 causing issues

on my RedHat 7, i noticed that network connection for Netbackup stopped working and i tried everything including rurning off my firewall and disabled SELINUX with no luck. the only thing i noticed ...
0
votes
1answer
81 views

How to close nc port in Debian 9?

I am struggling to close these ports which seem to be backdoors -- or at least I have never opened and used them. How can I close or shutdown nc and close these ports? netstat -lntup | grep nc ps-...
-1
votes
1answer
34 views

Restrict inbound access on localhost:TCP port

For reasons beyond my control, I have a binary that binds to TCP "localhost:$PORT". (Unix socket bindings would make this question moot). If I understand correctly, this means that although no ...
0
votes
1answer
36 views

Blocking ports with iptables 1.4.2

I am trying to block some ports on an embeded uClinux· The Iptables version is 1.4.2. The command I used was iptables -I INPUT -p tcp --dport 22 -j DROP But it seems that iptables 1.4.2 is not ...
0
votes
2answers
57 views

Telnet - how to verify why a port is blocked?

We have linux machines with RedHat 6.5 operating system. When we try to telnet to localhost on port 8182, we get connection refused: service iptables status Firewall is not running telnet localhost ...
0
votes
1answer
262 views

nginx: Can't bind to port (already in use) although no tasks running on that port [closed]

i just chose nginx for my webserver and I did follow this tutorial: https://github.com/groovemonkey/hands_on_linux-self_hosted_wordpress_for_linux_beginners However, I just can't connect to my ...
0
votes
2answers
647 views

SSH Remote port forwarding with multiple ports

For those who worked with ssh port forwarding or for those who have an idea, I managed to create a remote tunnel from my PC to a remote machine(a camera that does not have a public address) through a ...
0
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2answers
122 views

iptables allow everything, is it safe?

The os is Ubuntu Server 18 and I am running a web server on it. Is it safe to accept all traffic on all ports? iptables -P INPUT ACCEPT iptables -P FORWARD ACCEPT iptables -P OUTPUT ACCEPT I tried ...
1
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2answers
3k views

How to check which localhost's ports are used on the terminal? [closed]

I'm working on the Linux Ubuntu terminal and I'm wondering how to check directly on terminal which localhost ports are used please ?
0
votes
1answer
88 views

Which ephemeral ports are used with raw sockets

Referring to How source ports get assigned, I do know, how the local port is determined. (=> Random free ephemeral port). However, why does my raw socket using socket(AF_INET, SOCK_RAW, IPPROTO_TCP) ...
0
votes
2answers
517 views

systemd opens socket, service fails to bind to this socket

I am working on RedHat7.5. I made a systemd socket (/etc/systemd/system/barfoo.socket): [Unit] Description=This is the barfoo socket [Socket] ListenStream=0.0.0.0:123 NoDelay=true BindIPv6Only=both ...
2
votes
1answer
235 views

IPv4 and IPv6 sockets with same port

Is it possible to have a single process that would have two sockets, one using the AF_INET and one using the AF_INET6 families, while both being bound to the same port number, e.g. 20000? If the IPv6 ...
0
votes
1answer
170 views

Chainging proxychains DNS port

I am using a proxychains on Kali with a DNSCrypt nameserver which operates on port 443. When I start proxychains it tries to connect to the DNS server on port 53 and it returns a timeout. How can I ...
0
votes
2answers
76 views

remap port 80 to 22

I would like to remap incoming requests on port 80 to port 22 and tried the following: sudo iptables -A PREROUTING -t nat -p tcp --dport 80 -j REDIRECT --to-ports 22 but still, ssh -i key user@host -p ...
1
vote
0answers
19 views

Regulating user-daemons from listening on unprivileged ports (preventing server spoofing)?

If I have a port >1024 but that I want to reserve to one executable how can I ensure that no other executable can open and listen to a socket on that port? /usr/bin/foo_srv -p 8080 /usr/bin/bar_srv -...
-2
votes
1answer
32 views

How to change the port number for any service? [closed]

I know how to change the port number through the config file of sshd but I want to know how do you change any port number for any service without going into the sshd condfig file or for any service in ...
0
votes
3answers
1k views

Port open/listen but no associated process

In the output of nmap -p- localhost I get an unknown open tcp port, that's different at each reboot. How can I determine which process opened it and listens through it. I tried many of the usual tools ...
-1
votes
1answer
55 views

How to open up a tcp server compatible with tcpgoon

I have tcpgoon installed on one computer, provided that there is a direct VLAN connection, how do I create a TCP server on my second computer?
16
votes
5answers
4k views

How do I get only the PID, without any extra information, of a process running on port 3000?

I'm using CentOS 7. I want to get the PID (if one exists) of the process running on port 3000. I would like to get this PID for the purposes of saving it to a variable in a shell script. So far I ...
0
votes
1answer
181 views

Two local address listening on same port?

How is it possible that netstat -a | grep 8081 shows this: localhost.8081 *.* 0 0 49152 0 LISTEN *.8081 *.* 0 0 49152 ...
1
vote
1answer
967 views

Opening port not working

I have a python server running on port 8000 on a raspberry pi and would like to make it accessible within the local network, which is currently not working. The interface wlan0 is configured with ...
2
votes
2answers
1k views

Cannot start Springboot as init.d service on port 80

I've been following the official guide to setting up Springboot as an init.d service on an Amazon Linux ec2 instance. Before I got to this setup, I was running into the problem where I could not start ...
-2
votes
1answer
56 views

How to install MySQL on Ubuntu with a particular IP address on a particular port?

How do I install MySQL on ubuntu 14.04 with the bind address as a particular IP address on port 1723?
2
votes
2answers
1k views

Allow apt-get through iptables that drop everything [Ubuntu]

I have my iptables set up to drop everything by default in the INPUT, OUTPUT, and FORWARD rulebooks. But I need to allow connections through port 80 (HTTP) and all incoming TCP/UDP requests on port 53 ...
1
vote
1answer
290 views

Create lock using unix socket/port

Is there a way to hold a lock a unix port using netcat or some other command? I want to do something like this: set -e; nc -lock 8000 & # this needs to fail if another process holds the lock ...
0
votes
0answers
56 views

Determine the cwd of running process, or use a marker to designate process

I am a software project and I need to have several processes running at once to develop it. When I start one process using: ./scripts/run.sh in that script I want to check if another process is ...