Questions tagged [tcp]
TCP stands for Transmission Control Protocol and is one of the core protocols of the Internet Protocol Suite. TCP complements the Internet Protocol (IP), and therefore the entire suite is commonly referred to as TCP/IP.
339
questions with no upvoted or accepted answers
6
votes
0
answers
3k
views
Android TCP error failed to resolve host name from static library
I'm using ffmpeg on android and i have encountered and error, that does not occur when i'm using the library on my linux VM.
I'm using FFmpeg Static Builds, from here.
I am using the stable 3.1.5 ...
- 161
5
votes
0
answers
8k
views
How do I kill existing network connections on Linux?
I've been working on a project that is nearly complete: to be able to kill my children's internet connections at the touch of a button. I've implemented part of the solution by basically calling:
...
- 71
4
votes
1
answer
929
views
What happens when I terminate a process and the socket send buffer is not empty?
In Windows (and probably in other operating systems), if a process has a TCP connection with another process on another machine, and then I terminate the process, an RST packet will be sent to the ...
- 41
4
votes
0
answers
583
views
Samba not connectable "Go away, we're not home"
I'm having an issue connecting to my dedicated server using samba. The server is a debian (squeeze) box running a samba server, only small modifications have been made to the default config and the ...
- 220
3
votes
0
answers
2k
views
How to access to a SQL Server Instance from a WSL2 Debian System?
I would like to connect from my WSL 2 Debian System to a SQL Server instance. This is because I want to develop an cossplatform app in Python and make some tests.
WSL 1
As far as I know with WSL 1 I ...
- 181
3
votes
0
answers
2k
views
Force windows to communicate to specific ip addresses via specific network card
Hello I'm currently facing issues with tcp communication on a windows 10 system with two network cards.
I need to connect specific hardware which is in a LAN.
Sometimes windows uses the network ...
- 31
3
votes
1
answer
1k
views
Cannot connect to RPC server over TCP on WSL
I'm currently running an RPC (TCP) server in ubuntu (19.04) inside the WSL(2) in windows, listening to 0.0.0.0:7860. If I run any query inside the WSL(2) itself with address 127.0.0.1:7860 it works. ...
- 131
3
votes
0
answers
516
views
PHP cURL's TCP_FASTOPEN option is not available
According to php.net, the PHP cURL option CURLOPT_TCP_FASTOPEN is available since cURL version 7.49.0 and PHP version 7.0.7.
According to what phpinfo reports on my server, i'm running PHP 7.3.7 and ...
- 31
3
votes
1
answer
1k
views
Slow TCP/IP and UDP communication
I am working with a device on a metal cutting machine that communicates using TCP/IP or UDP over Ethernet. I wrote a test program that writes and read ten registers and times how long it takes for the ...
- 151
3
votes
0
answers
2k
views
Destination Host Unreachable between linux boxes
I have a home wifi network with 2 linux and 1 mac system. I can reach each linux from mac and other way round, but an attempt to ping a linux from another linux results with "Destination Host ...
- 131
3
votes
0
answers
819
views
Inactive / Unknown TCP connections
I can see the following TCP connections in one of my linux host.
root@odb-us:~# netstat -a | grep ESTAB | grep 10.12
tcp 0 0 odb-us.:2424 10.12.0.77:40000 ESTABLISHED
tcp 0 ...
- 31
3
votes
0
answers
721
views
IPv6 Causes TCP SSL requests to Microsoft CDNs to fail (connection reset)
NOTE: The following only applies if I enable IPv6. If I disable IPv6 via control panel/adapter settings in Windows everything works fine. See latest update at bottom.
Windows 10 Desktop
-> Wired ...
- 241
3
votes
1
answer
1k
views
Is it necessary for an RST packet to have an acknowledgement number?
I am studying about TCP reset attack. I know that some RST packets have an acknowledgement number (with the ACK bit set), and some RST packets do not have an acknowledgement number (the ...
- 31
3
votes
0
answers
8k
views
DBus over Network (TCP)
I'm trying to communicate with a remote DBus (i.e. IP 10.100.20.101) from a host (i.e. IP 10.100.20.102) - X86_64 platform to ARM development board.
I've tried the solutions from here but it caused ...
- 31
3
votes
0
answers
394
views
Force local packet pass trough the router (or disable loopback) - windows 8
i would like to avoid that packets sent from my machine to the same machine (via the IP assigned by the external router eg. 192.168.1.20) are routed with loopback and so never reach the external ...
- 131
3
votes
0
answers
1k
views
Is it possible to edit TCP and UDP packets?
Is it possible to edit the UDP and TCP packets a program sends? For example, we have a program that sends some information to its server. But we don't want to send some information that might be ...
- 3,030
3
votes
0
answers
7k
views
Iperf tests in reverse direction
I used iperf to measure the max throughput for TCP connection between two ubuntu machines. Both the machines were directly connected be means of a 1Gbps cable. When I performed iperf tests i obtained ...
- 141
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 ...
- 131
3
votes
1
answer
2k
views
Maximum TCP session time on Linux
I have two python scripts, which reside on different machines and are connected by a TCP connection. If the scripts do not share any data, they send dummy packets, so that the session is never idle ...
- 131
3
votes
1
answer
491
views
How do I prevent connection resets upon pulling the ethernet cable?
In Windows, when you pull out (trip over it) a network cable, then the connections get reset.
If you do the same on a Linux box or if you put a switch between PC and router and then pull the cable ...
- 186
3
votes
2
answers
267
views
Why does the IP address matter to IE9?
Start up Wireshark.
Point IE9 to a local, nonroutable IP address. You will see a single TCP SYN packet try to connect to the host.
Now point IE9 to a remote, routable IP address. You will see 2 ...
- 489
3
votes
0
answers
665
views
Create a VNC proxy with authentication
We have a bunch of VNC servers located on our local network. We wish to give external customers access to these VNC servers, via some sort of "middle-man" software solution which can handle ...
- 277
3
votes
0
answers
1k
views
iodine fails its ping test
I'm trying to get iodine working on my Ubuntu machine.
The server is working fine, but when it try to establish a connection, and change the route table using the default iodine-client-start script i ...
3
votes
2
answers
1k
views
How to increase transfer speed on fat long pipe?
I have a log pipe between two facilities (gigiabit circuit with RTT latency of 17ms). When doing system-to-system file transfer (file sharing, rsync, ftp, sftp) I'm hitting maximum speed of approx 30 ...
- 133
2
votes
0
answers
460
views
TTL getting changed while pinging local network printer
When i'm pining a local device (NW printer) from win-10 PC using cmd, the TTL changing from 64 to 255 and again back to 64 continuously.
Kindly share the probable cause for this. see below..
Reply ...
- 21
2
votes
1
answer
669
views
Why does my virtual machine (Debian on Proxmox) not respond to a TCP SYN of another VM even though it arrives?
I got a very strange problem and I am out of ideas to solve it. I hope anyone over here has a helpful idea.
Some info about the virtual machines:
VM0: Debian 10 - 192.168.10.102 [+ 2 more interfaces]
...
- 41
2
votes
0
answers
736
views
What's the minimum upstream bandwidth required for ACK packets in a TCP connection?
Consumer internet connections often feature asymmetrical bandwidth with just 10% of even 5% of upstream speed compared to downstream, for example 1000MBit/s downstream with 50MBit/s upstream speeds.
I ...
- 221
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
2
votes
0
answers
335
views
How to calculate effective throughput from link speed, packet loss (%) and delay information?
I am working on a networks assignment where two linux VMs (say client and server) are connected by a bridge and I have to use ftp (vsftpd) to send a 100 MB file from client to server. I have set the ...
- 21
2
votes
1
answer
1k
views
What would prevent a TCP server port (once closed), from being re-opened right away?
I have a server program that uses TCP.
Sometimes, I need to restart the program for updates, or any other reasons, but when I do, the program closes the server port, and then once it restarts, it ...
- 95