Questions tagged [tcp]
The Transmission Control Protocol (TCP) is a core protocol of the Internet protocol suite.
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How can I block incoming TCP and UDP ports under Sequoia 15.7.2?
Update: Based on the responses that I have gotten so far, I realize now that I did not word this question very clearly, and also, that I initially misunderstood one of the comments in response. I ...
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How to know if TCP keepalive is enabled on a socket?
I have a long lived TCP connection used for a PostgreSQL database that appears to get disconnected from time to time. The database client runs on macOS Tahoe and unfortunately I don't have access to ...
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Is there way to disable tcp timestamps in macOS?
I am using macOS Ventura 13.3. I know that in Windows and Linux I can enable/disable TCP timestamps via netsh and sysctl commands.
In Linux, it is the net.ipv4.tcp_timestamps parameter. macOS has the ...
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How to properly trigger path mtu discovery
I've activate the pmtu attribute in my machine.
sysctl net.inet.tcp.path_mtu_discovery
net.inet.tcp.path_mtu_discovery: 1
then I've used /usr/bin/nscurl to send messages to a remote gateway with mtu=...
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weird connection request on macos m1 nettop
I see a weird connection request on macos m1 for nettop. This happens on other programs as well. these ips are blocked, but I am wondering what is causing this.
This happens specifically on macos, ...
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Macbook Pro - How do we terminate ALL ESTABLISHED connections?
How do I terminate ALL the ESTABLISHED tcp connections in Terminal?
I can use the command below to get a list of active & established connections:
netstat -anvp tcp | awk 'NR<3 || /ESTABLISHED/‘...
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Detect which process is attempting TCP connections
On my MacBook Pro (Monterey), I was looking at packet captures over a period of a few hours and I noticed that something on my box is, every few minutes, pinging other computers on the local network ...
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Strange Ports opened on my Iphone?
I've run NMAP several times on my home network in my campaign of learning the basics of network security.
So far all my devices except my PC have been Iphones/Chromebooks so nothing has been found in ...
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What is the Bonjour service _acp-sync._tcp used for? And why is it accessing my Apple AirPort Base station using a long and obscure string?
Scanning for Bonjour devices on my network shows a long and obscure string associated with my AirPort Base station using this Bonjour protocol _acp-sync._tcp. What is this? What is it for?
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Reset TCP/IP Stack without Rebooting?
This is a bit of an unusual question but I have a Mac server that gets hit with a lot of DDoS attacks. Usually my data center's mitigation system catches them but sometimes they slip through. When ...
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What is `intu-ec-client` listening on TCP port 8021?
I'm wondering how I can either kill it or change the port it listens on.
Neither lsof -nP -i4TCP:8021 | grep LISTEN nor netstat -av | grep 8021 or launchctl list | awk 'NR>1 {print 3ドル}' | xargs -I %...
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Blocking SYN-Flood Attacks?
I've got a Mac web server that's been getting hit pretty regularly with SYN half-open attacks. I've looked in to various ways to combat this. I've found a lot of general information, but not very much ...
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Why my mac can not access external traffic to other port except 80, 443, 22?
I can access all website with standard port(80 and 443) example: domain.com, but why I cant access example.com:3030? I cant connect to MySQL and PostgreSQL, via direct host/port to external IP, but I ...
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sysctl setting net.inet.tcp.keepidle removed in 10.15. Is there a replacement setting?
My work requires long-running connections to databases that required this sysctl setting in earlier OSX versions. Since it no longer exists, these connections appear to remain open, but they ...
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Can't connect to TCP/IP printer with undescore "_" in the IP
I have a wireless printer that's connected to our private LAN in our workplace. There is a weird configuration for the printer that it requires two printers to be added. For color - 192.168.51.xxx and ...