The old SSL certificate has expired and I want to renew the SSL certificate. However, the server already has established multiple links with other clients. So, can I just bind the old sockets to the new ssl, which means I don’t need to disconnect the old base tcp links? Answer Existing TLS connections don’t need to get updated with a
Tag: tcp
How does the host name resolution of anyname.localhost resolves to IPv6 ::1 address?
In an Ubuntu 20 or 22 LTS, if I attempt to use a hostname like anyname.localhost it always seems to resolve to IPv6 ::1 address. In an old RHEL 6, if I attempt to use a hostname like anyname.localhost it always seems to resolve to IPv4 127.0.0.1 address. In a MS-Windows or MacOS 12.6 machine, this does not seem to
When using recv(n), with n greather than the MTU are you guaranteed to read at least a whole layer 2 frame?
I was wondering, imagine if there is no data to read from a TCP socket, then a whole frame of 1492 bytes arrives (full). In your code (C or any language supporting TCP) you have let’s say recv 4096 bytes, will the OS guarantee that the recv reads the whole 1492 bytes, or is it possible that the loading of
Parallel TCP connection using threads
I am trying to build a system that opens parallel TCP sockets using threads. My threads are triggered using message queue IPC , thus every time a packet arrive to the message queue a thread “wakes up” , open TCP connection with remote server and send the packet. My problem is that in Wireshark , I can see the the
Is a connection to localhost copied over memory or disk?
AFAIK, there exist two methods for IPC over sockets. Unix sockets and TCP/IP sockets. UNIX domain sockets know that they’re executing on the same system, so they can avoid some checks and operations (like routing); which makes them faster and lighter than IP sockets. They also transfer the packets over the file system, meaning disk access is a natural part
How can I create a TCP connection in Python between 2 PCs
So far I have made a VERY basic client/server application that creates a TCP connection. I have a lot of programming experience, just never did this low-level stuff and especially nothing with networks. Note that all the prints are just to help me figuring out what is going on. One of the known issues is that jsonip sometimes gives me
TCP echo server doesn’t accept client
I’m trying to make an echo client server in C. The problem is, when I start the server and run the client code, in client shell it says “Connected” but in server shell it still says “Waiting for connection”. (Server doesn’t say “accept failed”. It says “Waiting for connection” forever). I think server is not accepting client and therefore if
How can I stop the while?
I have A TCP Server-Client where I enter a number with the number of times that I want to send the word to the server. So I send correctly because I print the information on a loop(in client) but in the server shows infinitely because I put while(1) but if I don’t use just print it one time. I don’t
What happens to TCP socket when IP address changes?
Is there any error on a socket when writing to it after IP address change? In my I’m using TCP socket, both read/write (non-passive), no TCP or application keep-alive. To inspect this case I use socat to connect to a simple echo server on my local network. The connection is OK until I change the client IP address on my
scapy takes infinite time sending TCP SYN packet with no reply.
I want to send a simple SYN request to my router to get an ACK response in a bid to learn network (TCP/IP) using python and scapy. But scapy is taking a long time of getting any answer. script- What is the solution ? Answer So to summarize, you need to reverse IP and TCP order. What people call TCP/IP