Questions tagged [tcpip]
Transmission Control Protocol (TCP) and Internet Protocol (IP) provide end-to-end connectivity specifying how data should be formatted, addressed, transmitted, routed and received at the destination.
400 questions
0 votes
1 answer
499 views
What does a connection and a session actually mean?
I’ve come across both “connection” and “session” in networking, but I’m unable to grasp the exact meaning of those two terms and how they differ. What defines a connection in a protocol like TCP, and ...
2 votes
0 answers
70 views
Sniff traffic between 2 devices
I have an Android phone with an app that controls an AV receiver, which sits on wired Ethernet that goes into a switch that goes into another switch that goes into the router, which also carries the ...
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1 vote
2 answers
116 views
Why does adding a new route on macOS not affect existing TCP and UDP connections?
This shouldn't be happening since routing is IP-level phenomenon, and yet it does: Establish a TCP (or even UDP!) connection: nc 1.2.3.4 1234 Observe that you can send and receive data via this ...
3 votes
1 answer
304 views
Second network connection makes internet unreachable
Periodically, my Windows desktop PC is connected to two networks simultaneously. The first network is a Wi-Fi network that is also connected to the internet via a Wi-Fi router/DSL modem. The router ...
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1 vote
0 answers
178 views
How to wait a server for SSL handshake using Curl?
I need get a website using Curl but the server does not respond the SSL connection and Curl says an error on the 2 minutes but the server respond in the minute ~5. I try to use the timeout argument ...
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0 votes
1 answer
4k views
Use windows 11 to forward traffic between 2 LANs
I have Windows 11 with IP addresses 192.168.72.100, 192.168.10.113, connected to two LANs: 192.168.10.1/24 192.168.72.1/24 From a host on 192.168.10.1/24, I would like to ping, and http/vnc to machine ...
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2 answers
242 views
How to determine if one IPv4 address is visible from another?
I am learning TCP/IP networking, and am having a bit of trouble putting it all together into a working understanding. I am wondering how one can determine whether a packet from one host can reach ...
0 votes
1 answer
739 views
My download speed is decreased in browsers after making changes in registry and running commands
I watched a network optimization video for Windows on the internet and did some changes on my PC according to the video. After what I did, I realized when downloading something via Brave it took ...
0 votes
1 answer
127 views
How do we reach an IP address?
How does the following work in TCP/IP protocol? There are two subnets: subnet A is 10.0.0.0/8 subnet B is 10.20.0.0/16 A host in Network A with an IP address of 10.20.3.4 wants to access a host 10....
2 votes
1 answer
238 views
Are extra flags discarded in TCP exchanges?
A "normal" TCP handshake looks like this: MachineA → SYN → MachineB Machine B → SYN,ACK → MachineA MachineA → ACK → MachineB This means that for each step, a flag (or set of flags) is ...
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0 votes
1 answer
856 views
Tunneling all TCP/UDP traffic through one port
My PC doesn't have a public IP, so I want to use a VPN with support for port forwarding for the following applications: Remote access software Home Assistant SSH LM Studio A1111 (gradio) ... and ...
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0 votes
1 answer
756 views
PostgreSQL traffic analysis - Wireshark - how many bytes in total are being received by the client?
<TL;DR> How many bytes are being received in total when a SELECT * command is issued for a (small) table? </TL;DR> I have a PostgreSQL table - very simple (see fiddle here): CREATE TABLE ...
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0 answers
424 views
Windows can't connect more than 64k concurrency outgoing connection
I'm trying to make 100k concurrency outgoing connection from one pc to my local server. My program can use specific ip on each connection. Goal : 1 pc have around 100k concurrency outgoing connection. ...
1 vote
1 answer
208 views
Is there a way to setup manual TCP/IP configuration on MacOS only for specific networks?
I need to have a static IP address only when I connect to the network generated by a custom device that I have. Is there a way to do this operation automatically without having to type IP, gateway and ...
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0 votes
1 answer
143 views
Defining Inbound and Oubound Policies in Windows Firewall,AV Firewall
In Windows Firewall we define Inbound & Outbound Policies for Web, Network, etc. access as we have separate settings for the same...The same if taken in an AV Firewall for example in Quick Heal ...
2 votes
1 answer
10k views
Windows 11 network settings keep changing to static IP with blank configuration
Dell XPS 15 9510 Windows 22H2 (22621.1485). This problem has persisted through multiple Windows 11 updates and multiple Dell driver updates. About half the time when I boot my laptop up at work, the ...
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10 votes
2 answers
8k views
How many TCP retransmissions Internet traffic is considered normal for a basic home setup?
Out of curiosity, I connected my laptop with an ethernet cable to the router and fired up Wireshark to understand and 'visualize' what's going on. Some packets caught my attention. I was having some ...
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1 vote
1 answer
62 views
Connection to website fails
I am trying to connect to a website. From my laptop, located in my WLAN, it doesn't work: joesse@laptop~> ping -c 1 www.ttrss.info PING www.ttrss.info(vps-4c11fdd7.vps.ovh.net (2001:41d0:304:200::...
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1 vote
1 answer
104 views
Low Windows bandwidth in google cloud platform
I have an on-premise site with mainly Windows resources and an up-to-date Forti firewall as the central communication device. This site is connected through a partner interconnect created according to ...
0 votes
1 answer
62 views
I am not able to send an audio or video file in chat software (such as WhatsApp, etc.)
My question is about data transfer on the Internet... What is the difference between split packets by open-source software and TCP/IP structure on the internet for split(MTU fragmentation and sequence ...
0 votes
1 answer
282 views
How are IP addresses and port numbers encapsulated down the TCP/IP stack?
This apparently senseless question keeps spinning in my head. I probably wrongly assumed that the Layer 7 headers for different protocols included the source and destination IP addresses and port ...
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0 answers
919 views
Torrenting now fails in Windows 10
qbitTorrent stopped working in Windows 10, so I uninstalled it, and replaced it with Deluge. 64-bit Deluge fails with "Unhandled exception in script Failed to execute script 'deluge-script' due ...
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0 answers
467 views
ICMP 3 / 3 if a port is unreachable
When I want to connect to a non-opened port of my Linux-PC from my Windows PC my IP-stack runs into a timeout after some seconds. So what's happening here ? Does my Windows PC not evaluate any ICMP ...
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0 votes
0 answers
835 views
How do I stop TCP reset packets?
Full story: This has been quite the odyssee, finding out who is sending these TCP reset packets. The isp pointed me in the direction of the minecraft server, the minecraft server said it has to be the ...
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16 votes
6 answers
9k views
Why don't we have a usable IP address in 127.0.0.0?
From theory, each part of an IP address is a number between 0 to 255 (256 usable slots in total). But why is 0 not used in any IP addresses in their 4th part and they always start from 1 in IP ...
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28 views
how to change my IP address to another country? [duplicate]
I need to access that website which is allowed to be accessed from Syria. I have tried to change my IP address to make my device as Syrian device. however my attempt went wrong. here are my steps: I ...
0 votes
1 answer
329 views
Why does Windows resolve all IPs of all NICs with the hostname?
I´m having diferents problems with TCP/IP aplications that works through HOSTNAME. The Server where this aplications are installed(WIN Server 2012) have 4 NICs and Windows,resolve his own hostname ...
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-1 votes
1 answer
811 views
How do computers know how to use TCP
I'm asking from a Windows perspective but any perspective is great. Are NICs all a computer needs to interface with TCP? Wouldn't they also need some sort of software associated with TCP, or is that ...
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0 votes
0 answers
161 views
VM can access internet despite iptables DROP rules
I have installed VirtualBox and I have 2 Ubuntu VMs running on VirtualBox. Please see the network diagram: VM 1 (Client VM) has static IP address of 10.0.2.2. Gateway VM has 2 IP addresses - 10.0.2.1 ...
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0 votes
0 answers
1k views
How can I restore default settings and metrics in Windows Server 2019?
I have a Server 2019. With RAS installed and I have three NICs. I played around with the standard gateways to connect an IIS to the second NIC. Now I want to reset all routing and metric changes to ...
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1 vote
2 answers
165 views
A Dos attack possibilty using IP Datagram and TTL
So I recently learned about the whole IP Datagram and its headers. We learned about the TTL field that exists because sometimes a packet from a certain network id will be sent to another router, but ...
0 votes
1 answer
351 views
network bridge query with hamachi?
I have an embedded hardware in one city connected with my mac laptop via ethernet. I wish to connect that hardware to the server in a different city. The server is not on the internet but I have a ...
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0 votes
1 answer
891 views
Address of a Transport layer?
In TCP/IP protocol stack following protocol level addresses exists: Data Link layer - MAC address Network layer - IP address Transport layer - ? Application layer - Socket address which is ...
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2 votes
1 answer
3k views
MAC address in TCP Header - HTTP Request?
In the same below, why are there MAC addresses in the respected request packets? Why and how did the client obtain the destination MAC address? At first I thought it was the router, but can this ...
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0 votes
1 answer
3k views
How to resolve VLAN tagging issues with Google Nest WiFi router
I am a software engineer and have some training and experience with TCP/IP networks, but not enough to figure out this intractable issue that appears to be caused by my choice of router colliding with ...
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1 vote
1 answer
665 views
Scenario where DHCP static lease AND static IP (both with same IP) on same machine?
OK the obvious answer is that "this is stupid", but please read the scenario. Let say, we have a very sensitive piece of equipment (like an alarm system), that we want to eliminate as many ...
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0 votes
1 answer
279 views
is "Empty reply from server" a deliberate reply, or a default one from the TCP/IP stack?
I have a device whose port 80 is open and I was wondering what is behind: ~ # curl -v http://192.168.10.253 root@srv * ...
- 3,937
0 votes
4 answers
169 views
What is a (sub)network in the context of TCP/IP stack?
In the context of TCP/IP stack (that is the Internet), is a (sub)network defined as IP address + mask? If not, then how is a (sub)network defined? Clarificaltion: Given a complex interconnection of ...
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1 vote
1 answer
744 views
How to connect to HW device on IP address ending with .255?
I have HW device with web settings interface (similar principle like router, but it isn't router) and I changed the IP address of the device to .255. I know it is an broadcast address now and I'm ...
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3 votes
1 answer
1k views
When will the router remove an entry from its NAT table?
When will the router remove an entry from its NAT (net address translation) table? Most routers used in our homes maintain a NAT table to translate the public IP and port to the private ones. This is ...
1 vote
3 answers
259 views
How to diagnose issue with browsing websites?
I've had an issue with my PC which started yesterday. After reboot it works fine for about 10 minutes, then i'm unable to browse any websites from Firefox, Chrome or Edge. Rebooting again fixes it for ...
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0 votes
1 answer
1k views
Connect adb wifi without using tcpip Android
I am using a Nokia 5.1 plus and my computer is Dell Latitude E6430 ETG model. I'm using adb Wi-Fi and running it through cmd to run my application in mobile without using a cable. I'm doing all these ...
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0 votes
1 answer
4k views
Windows 10 Data Usage Not Showing Up Properly
When I try to check my data usage in Windows 10 (ms-settings:datausage) my data usage doesn't show up. On the main screen it says 0MB. When I click "View usage by app" to get more detailed information ...
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3 votes
1 answer
4k views
Tool to send TCP RST flag
Since yesterday, we have strange traffic to our server that is causing it to consume up all memory over time. This is the pattern: time (sec) info ...
1 vote
0 answers
125 views
How do Flow Control and Congestion control work together?
I am trying to learn about Flow Control and Congestion Control in TCP. So far I understand that flow control uses the sliding window method and the receiver advertises a receive window based on how ...
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0 votes
1 answer
138 views
How is network congestion detected in TCP?
I am trying to learn about Congestion Control in TCP and in this video (at 1:56), he says if there is no ack received, it assumes network congestion and cuts back the cwnd, no where he mentions about ...
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1 vote
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How to disable Path MTU Discovery on Windows 10
How can I disable Path MTU Discovery on Windows 10? Following these instructions for an older Windows version, I tried adding the EnablePMTUDiscovery registry value to HKEY_LOCAL_MACHINE\SYSTEM\...
0 votes
1 answer
371 views
Is an open port on Router a threat if it's forwarded to a host which not exist
Consider we have port 65434 open on router (open for WAN). The port forwarding is done to a host which does not exist. Can a hacker exploit this open port on router which leads nowhere?
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1 vote
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Will the MS Windows RDP connection be a security threat if
I have read a lot regarding this subject, but still not much is clear. So the question is: will it be dangerous to use RDP for connections outside LAN if?: I have a special module which have ...
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3 votes
1 answer
2k views
How does port triggering know what ports to open?
Port Forwarding as I understand it When creating a port forwarding rule, the router keeps the specified external port open at all times, and simply forwards all inbound traffic for that port to the ...
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