All Questions
Tagged with tcp networking
477
questions
-1
votes
0
answers
20
views
My download speed is decreased on the browsers after these changes
I watched a network optimization video for Windows OS's on the internet and did some changings on my PC according to video. After what I did, I realized when downloading something via Brave it took ...
0
votes
1
answer
37
views
How to simulate Hercules on local IP address?
I would like to simulate a TCP server, using Hercules (by HW-Group).
When I configure the port (12714), netstat -aon | findstr "12714" shows me this result:
DOS Prompt>netstat -aon | ...
- 465k
0
votes
1
answer
52
views
How do we reach an IP address?
How does the following work in TCP/IP protocol?
There are two subnets:
subnet A is 10.0.0.0/8
subnet B is 10.20.0.0/16
A host in Network A with an IP address of 10.20.3.4 wants to access a host 10....
- 9,996
0
votes
1
answer
5k
views
Client not sending ACK packet in response to SYN-ACK
I'm seeing a weird network behaviour with my TCP 3-way handshake in my home lab.
Setup is from my Windows 10 host on one network, through pfSense, and into an Ubuntu VM on a different one. Firewalls ...
CommunityBot
- 1
2
votes
1
answer
4k
views
How to Maintain an Inactive Tcp Connection?
If a TCP server establishes a TCP connection with a TCP client and the TCP client never sends any packet to the server.
I roughly know firewalls near the TCP server may send an RST to it. Or there is ...
CommunityBot
- 1
0
votes
1
answer
623
views
When is the TCP receive window advertised?
I am trying to learn about the TCP 3 way handshake and flow control. I was reading this and I understand that in the 3 way handshake the sender and receiver agree on the Sequence and Acknowledgement ...
- 159k
44
votes
5
answers
94k
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Accessing Windows localhost from WSL2?
I have Windows 11 with WSL2 (Ubuntu) installed on it.
I've setup a gdb listener server on my Windows localhost and want to access it from Wsl2, but it seems my Windows machine and WSL are using ...
- 23.6k
3
votes
1
answer
6k
views
SYN-ACK not received
On a standard TCP connection between server and client, I have this issue: the SYN-ACK is not received from the client, while it is sent from the server. I could see this on Wireshark from both server ...
CommunityBot
- 1
0
votes
0
answers
115
views
Linux netfilter: How to capture, modify and retransmit packets that my host is sending to a specific destination?
I am trying to write a linux service that captures the packets that go from my personal server to a specific destination and performs necessary changes to them. More specifically, i want to find all ...
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, ...
CommunityBot
- 1
2
votes
1
answer
184
views
Are extra flags discarded in TCP exchanges?
A "normal" TCP handshake looks like this:
MachineA → SYN → MachineB
Machine B → SYN,ACK → MachineA
MachineA → ACK → MachineB
This means that for each step, a flag (or set of flags) is ...
- 465k
2
votes
1
answer
768
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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: ...
- 465k
0
votes
0
answers
262
views
PowerShell: Diagnose timeout vs. connection refused on TCP port with Test-NetConnection
I frequently need to diagnose network connectivity issues and I'm currently using Test-NetConnection in PowerShell (Version 5.1). The output tells me if a port is reachable. In case it's not, I would ...
- 56
0
votes
0
answers
74
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
566
views
Tunneling through VPN over TCP
I'm currently trying to set up a VPN on my server to connect to from my Laptop.
The server is a command-line Ubuntu running on a x64 machine. The Laptop runs x64 Windows 7.
The VPN itself is already ...
- 43.2k