All Questions
21 questions
0
votes
1
answer
328
views
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 ...
- 101
1
vote
1
answer
623
views
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=...
- 631
1
vote
0
answers
47
views
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, ...
- 161
4
votes
1
answer
5k
views
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}' | xargs -I %...
- 211
1
vote
0
answers
170
views
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 ...
- 1,795
3
votes
2
answers
1k
views
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 ...
- 31
11
votes
3
answers
13k
views
Packet sniffer for MacOS Mojave and above
I'm looking for a packet sniffer app that runs on MacOS in a GUI (I know I can accomplish some functionality with native CLI utilities like tcpdump).
Previously I used Packet Peeper, however it doesn'...
- 258
0
votes
0
answers
3k
views
Why is IMRemoteURLConnectionAgent contacting a Charter IP address
I never use iMessage. I never use iCloud. And yet I happened to check my Mac's current network connections and I found this:
IMRemoteURLConn 33557 me 7u IPv4 ...
0t0 TCP 192.168.1.198:57996-&...
- 61
2
votes
1
answer
838
views
How does WireShark work on OS X? What processes does it interact with?
I'm looking for deep/detailed research into how the MacOS TCP stack works. Namely, what are the files/Dynamic Libraries that offer this service?
What Libraries does WireShark interact with?
My goal ...
- 4,593
2
votes
2
answers
4k
views
How to inspect TCP/IP packets
How can I inspect IP packets send through currently open TCP connections?
I opened a nettop utility in Terminal, which I think lists IP packet, but doesn't tell anything about their content, namely ...
- 2,755
0
votes
1
answer
369
views
How to increase value of tcbhashsize parameter in OS X
I am running OS X 10.11 - El Capitan. I am trying to tune my TCP setting for better network / Internet performance. Most of the settings I have been able to modify permanently through /etc/sysctl.conf ...
- 101
6
votes
1
answer
4k
views
How to Use Terminal for "Little Snitch" Functionality without Little Snitch
I'm a Terminal newb, and trying to wrap my head around manual "Little Snitch" functionality without using Little Snitch.
From the research I've been doing, I've landed on the fact that I need to ...
- 109
1
vote
2
answers
1k
views
How to put Wifi card in monitor mode?
When I run tcpdump, I do so after having connected to an access point.
Is there a way to run tcpdump without having connected already?
- 19
0
votes
1
answer
2k
views
How to enable echo service for tcp or udp on well-known port 7 on Mac OS X 10.8 or above?
I am learning TCP/IP protocol with a Mac, and need echo service (refer to [RFC 862], or Wiki) to test network. But it seems to OS X doesn't implement it or disable it.
I learned that launchd replaced ...
- 103
2
votes
1
answer
698
views
Find who is intercepting traffic on port 80
Every 7–10 days, all internet browsing on my Mac stops working. I can use Firefox, Safari, Chrome, but I'm able to surf only Google and few other sites.
So I tried to telnet a webserver on the local ...
- 121
3
votes
1
answer
6k
views
How can I limit bandwidth for a specific port/app in OS X 10.10 Yosemite?
I am running OS X 10.10 Yosemite, and I am looking for a way to limit upload bandwidth specifically on TCP port 8333, so I can run Bitcoin Core to contribute outgoing bandwidth without completely ...
2
votes
1
answer
2k
views
TCP Congestion Control Algorithm of OSX10.7
How can I find out which algorithm OSX10.7 uses (NewReno, SACK, Tahoe...) and if possible, how can I change it?
- 21
6
votes
4
answers
2k
views
Open ports. Safe?
My friend is currently running the default firewall with "Block all incoming connection" (except the basic ones like 80). I just scanned his mac for open ports and I found the following:
Open TCP ...
- 163
3
votes
1
answer
5k
views
Postfix SMTP server slow to accept incoming connection
I have a snow-leopard os-x Server configuration running postfix with no local firewall on the X-Serve.
When a client attempts to connect to the SMTP port the connection takes about 15 seconds to ...
- 317
2
votes
1
answer
440
views
How do I turn the echo service on in Snow Leopard?
I'd like to temporarily turn on the echo service (TCP and UDP port 7) on in Mac OS 10.6 (Snow Leopard). I guess this involves using the launchctl/launchd?
- 405
7
votes
1
answer
7k
views
How do you set the TCP congestion control algorithm on OS X?
I would like to set the TCP congestion control algorithm to Westwood+. Is this possible in OS X?
- 173