All Questions
20
questions with no upvoted or accepted answers
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
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
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
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
307
views
How can I use the "location of socket in memory" field in /proc/net/tcp
I'm working on a proxy for linux(C++) that, amongst other functions, keeps track of tcp connections and associates them with the process's pid. To do that, I get the inode in /proc/net/tcp and then ...
2
votes
0
answers
1k
views
Need help figuring out a random connection timeout issue on a server
I discovered this issue trying to loadtest a custom node.js websocket server, where some sockets are failing to connect (they hit the connection timeout). It does not appear to be related to the ...
- 121
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 ...
- 3,055
2
votes
1
answer
409
views
How does the Inetutils telnet utility determine if a connection is still alive?
I've started using sockets in programming with Java (I have experience with Python), and while testing a server that I'd written with the telnet command, I noticed that the utility responds ...
- 168
1
vote
0
answers
52
views
TCP server device for USB access readers
I have a BarCode reader that spits out data over a Virtual COM port (RS232 Serial) through a USB cable. I have a server running and managing a facility, and I need to read data coming off the BarCode ...
- 11
1
vote
0
answers
45
views
understand ss -to4 output for a jdbc connection
My application connects to a database over JDBC, and performs a lot of sequential inserts. There is only 1 JDBC connection opened by the application. As the performance is not as expected, I started ...
- 11
1
vote
1
answer
1k
views
sudo netstat -antp not showing PID
i am testing stuff with sockets and i encountered that strange case :
i coded i very simple tcp server in c, i made it block after accept(), just to see what happen when accepting multiple connection ...
1
vote
0
answers
211
views
Firewall : Is inbound required for getting response while Outbound rule already there?
I developed one MVC web application which have Web APIs and hosted in Amazon Instance and one windows application for calling those APIs for getting response from that server.
Both Web and Windows ...
1
vote
0
answers
27
views
Route only on output chain?
I have two machines A and B. I want to send iperf traffic from A to B, but first have it route through a userspace program on A. I did this with a tunneling device: therefore, I used the command ip ...
- 111
1
vote
1
answer
1k
views
Linux Kernel TCP socket functions
So I have been looking through the Linux Kernel v3.8.0-19-generic source code and I noticed that the proto struct, whose members are virtual functions for socket operations depending on the particular ...
- 215
0
votes
1
answer
245
views
How is an IP address assigned to a process in TCP?
When TCP connection is established between two sockets, suppose that there are multiple NICs in the computer, so which IP address will the socket bind [ or - which IP address will be passes into bind()...
- 11