All Questions
49
questions
0
votes
3
answers
396
views
Understanding how ports work and how are they different from processes?
I've been a part of a network operations team for quite some time now and was extracting a certificate using this command:
openssl s_client -connect <IP>:<PORT> </dev/null | sed -n -e '/...
1
vote
0
answers
264
views
why might nmap on a computer be reporting port 443 as closed on some but not all computers?
When I run nmap event-bridge.twilio.com on roughly half the computers in my network I get this:
PORT STATE SERVICE
443/tcp closed https
When I run it on the other half of the computers in my ...
- 7,212
0
votes
1
answer
122
views
Nobody listens on port, yet something accepts connection on it
Here is some background information first, although it may not be relevant to the problem.
I am learning Kubernetes and I set up a cluster where pi-hole runs as a service. I can access the admin ...
- 11
1
vote
1
answer
3k
views
bitcoin-cli testnet : Could not connect to the server 127.0.0.1:8332
I've installed bitcoin-cli from here
I run the bitcoin core on Ubuntu 20.04 (AWS EC2).
mac-os also experiences similar problems.
Ubuntu 20.04 screen capture for the error messages
The commands I've ...
0
votes
0
answers
844
views
What ports range is safe from taking by Windows 10
I wrote small program and I would like to use some TCP ports. Same ports for a longer period of time. The problem is each time Windows 10 wakes up it makes its mind which ports to reserve for its ...
- 740
0
votes
0
answers
479
views
How can I do a bi-directional Port-Forwarding (flow encapsulation)?
I have two applications: a client and a server which communicate through port 1234. For some reasons this port is blocked on our system but everything works correctly on port 1235 (checked with two ...
- 1
2
votes
0
answers
2k
views
WebSocket connections originating from local network all use same client-side port (instead of ephemeral) when connecting to local webserver - Why?
I set up a webserver on a virtual machine on my home desktop. I have my router forward several ports (80, 443, etc) to my desktop, when then forwards them via NAT to the virtual machine (see diagram ...
- 21
0
votes
0
answers
777
views
After opening port 443 in windows firewall as inbound rule, I cannot see it when I run 'netstat -an'
As an inbound rule on Windows 10 firewall, I added port 443 as TCP connection allowing all types of connections. However, I cannot see it when I run 'netstat -an'. How can I get it so that I see my ...
0
votes
0
answers
981
views
java.exe opens up hundreds of ports on 127.0.0.1 on a windows 10 computer and listens to itself
After I ran netstat -ab with admin right on my win10 computer, which is not running anything "java" related on the desktop nor there is "java.exe" in taskmanager's "detailed ...
- 103
1
vote
2
answers
2k
views
Packet reaches OS but not the process
Sorry if my issue is a bit hard to summarize in the title. That is the best I could come up with.
TL;DR Version: How do I debug when packets reach OS, but not the destination process?
Explanation: I ...
- 123
4
votes
1
answer
5k
views
How can I know what is preventing my socket to bind to localhost:50060-50959
I am using this Python code to listen to a port on my Windows 10 system:
import socket
for port in (50059, 50060, 50959, 50960):
try:
print(socket.socket(socket.AF_INET, socket.SOCK_STREAM)....
- 1,728
0
votes
2
answers
586
views
how to run mincraft server on linux
I wish to run minecraft server om my linux mint 19.0, but I have some troubles, I can start it in local, and connect by 127.0.0.1:25565 but i can't run it on my ip in inthernet, 4 example my ip is 2....
- 101
0
votes
2
answers
3k
views
ipv4 and TCP/UDP ports: Multiple instances of the same program, same port number
I am trying to learn about ipv4, TCP and UDP protocols. I have read that the purpose of a port number being assigned in a TCP or UDP datagram is to ensure that the sending/receiving machines forward ...
- 2,984
5
votes
1
answer
10k
views
How does TCP handle multiple requests targeted to one port?
As a server may get many requests from clients at the same time to a particular port, for example port 80 for HTTP objects, how does the server handle simultaneous requests?
- 153
1
vote
1
answer
3k
views
Using lsof and fuser I can't find the process listening on a strange port
I've read other posts about finding the process ID and what's listening, but sadly couldn't get my issue solved. So, apologize if I missed some info about it.
Running netstat I found a port that I ...
- 13