All Questions
157
questions
1
vote
1
answer
37
views
Capture TCP stream with tcpdump/netcat
I have a hardware device that hosts two separate TCP modules. One is for receiving commands from other machines, while the other is a TCP stream server that sends data based on the commands received. (...
0
votes
0
answers
306
views
Minecraft server using ngrok for port forwarding stopped working
So I built a PC using pieces I had laying around to make into a Minecraft server. I installed Ubuntu on it (I think it's the latest version because I installed it like a week ago. I didn't manage to ...
2
votes
1
answer
671
views
How to explain sequences of FIN,ACK instead of FIN - FIN,ACK?
Context: newly installed Debian 12, I get a bunch of strange logs related to ssh:
root@square:~# journalctl -u ssh -f
May 07 11:13:00 yop-square sshd[766]: error: kex_exchange_identification: ...
- 3,253
0
votes
0
answers
73
views
Linux 6.5 netfilter NAT reuses TCP ports in TIME_WAIT status?
In my understanding, Linux (netfilter)'s NAT doesn't reuse TCP ports in TIME_WAIT status, but seemingly Linux >= 6.5 reuses TCP ports in TIME_WAIT, even if the destination is the same.
For example, ...
- 41
0
votes
0
answers
60
views
Linux Server - Bandwidth test doesn't change during TCP Tuning process
I'm new to network administration and have a question.
I am conducting research on whether it is possible to carry out TCP tuning using the genetic algorithm method. To do this, I wrote a Python ...
0
votes
1
answer
850
views
How do I run a permanent tunnel in localxpose?
I am able to create a localxpose tunnel in ubuntu with this command:
:loclx tunnel tcp
but when I close my local connection to my server, the tunnel closes with it.
Is there a way to keep a tunnel ...
0
votes
1
answer
766
views
is it possible to OpenVPN connection UDP through SSH tunnel?
Hi i search a lot on the Internet, especially in this site and read more post and articles about using OpenVPN connection through SSH tunnel but all tutorials about using TCP protocol to do that. in ...
- 101
0
votes
0
answers
37
views
Seeing several thousand retransmits every 10 sec. via iperf3 on TCP traffic through a propritary network bridge device
What is the most likely cause of TCP packet fastACKretransmits when testing with iperf3 on a small 5-7 node Linus AutoIP network running on a TI AM5728 board? Where and what setting should we check ...
0
votes
0
answers
42
views
Teardrop detected from TCP ACK from myself
I'm experimenting with linux (Debian 5.10) networking to allow me to connect two networks (eg. 192.168.0.0/24 with 172.17.0.0/16) together.
Setup
In my case it is a small server with one NIC, hosting ...
- 126
2
votes
1
answer
2k
views
How to force `telnet` (in TCP mode) to send bytes immediately?
In Linux, when I run telnet <address> <port> and then type things, it buffers data and only sends collected line when I hit Enter. Furthermore, it buffers up to 4096 characters and ...
- 2,875
0
votes
2
answers
715
views
socat TCP server bidirectional using sleep, non-interactive client returns without response. Server reports: I/O error
I have the following TCP server:
socat TCP-LISTEN:10000,fork,reuseaddr SYSTEM:'read -r msg && sleep 3 && echo "OK"'
When I execute (interactive mode):
socat - TCP:localhost:...
- 738
1
vote
2
answers
9k
views
TCP to virtual serial port with socat
I have a program (program 1) that has a TCP server listening on port 1234. I have confirmed that the server accepts connections and sends data with a utility str2str.
Program 2, on the same machine, ...
- 73
2
votes
1
answer
628
views
Python TCP socket connection between Linux and Windows10 not working as expected
I am trying to establish a TCP connection and sending packets over a python socket server-client. I am using Windows 10 as my main system and VM Kali-Linux on the other side
I used Windows as a client ...
- 47
1
vote
1
answer
248
views
Possible to use shell script that does loopback to localhost when receiving a packet?
I want to run a shell script, that sends a packet to localhost (loopback) when it receives a packet from anywhere.
I am using netcat.
nc -lp $port, and then echo test | nc localhost $port works.
But, ...
- 21
0
votes
0
answers
1k
views
ModuleNotFoundError: No module named 'pyModbusTCP'
I am trying to run a python file on bootup which will collect some data from another device.
I created a service in the /etc/systemd/system directory
[Unit]
Description = File which requests data from ...
- 33