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.

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Multiple home routers

Suppose I have the following configuration: Router A: WAN port connected to the Internet, LAN = 192.168.1.0/24 Computer A: Connected to router A as 192.168.1.101 Router B: WAN port connected to ...
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1answer
58 views

What happens if all of the Ephemeral Ports are used in Windows?

If all of the Ephemeral Ports are used, and another socket tried to connect to a server, will the connection fail? or will the socket be assigned a port outside the range of the Ephemeral Ports?
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1answer
15 views

Access Point mode in USB WiFi adapters in Windows

Some USB Adapters, for example, many of the chips such as RTL8191SU, have option to set mode to either Station, or Access Point, or Soft AP. In Station Mode, it acts just as a WiFi client. In ...
0
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1answer
51 views

What is the default range of Ephemeral Ports in Windows 7?

I used the following command to get the Ephemeral Ports range in Windows 7: netsh int ipv4 show dynamicport tcp And the result was the following: Protocol tcp Dynamic Port Range -------------------...
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4answers
154 views

What layer of the TCP/IP do MAC addresses and IP addresses belong to?

Can anyone also tell me why we have 2 layered models(OSI AND TCP/IP)? Just having a bit of trouble with the question above. Can anyone kindly help?
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0answers
26 views

Windows: ipv6 version of “netsh int ipv4 install”

I need to reinstall TCP/IP V6 protocols on my Windows 10 64 bit PC. I know I can do this for TCP/IP V4 using netsh int ipv4 install in an elevated cmd prompt. When I run netsh int ipv6 install I ...
2
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0answers
433 views

Service to transparently use an HTTP CONNECT proxy on Linux

As our corporate network provides an HTTP CONNECT proxy for people who need to connect to the outside world, and as every Linux application needs to be set up specially to use it, I was thinking about ...
8
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3answers
21k views

How to generate UDP packet

I want to generate UDP packet to test a program, something equivalent to using telnet to test TCP port (Can telnet generate UDP packet?) How can I do this?
0
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1answer
713 views

FTPS - Can't Open Data Connection over WAN

Here is my setup, 1 Windows 2008 R2 Standard Box /w G6 FTP Server installed G6 is configured to use explicit SSL connections only (TCP:990) 1 WatchGaurd Firebox Firewall (between server and internal ...
109
votes
3answers
225k views

What are CLOSE_WAIT and TIME_WAIT states?

When I do netstat -a on my Windows machine, I get a listing of the ports with one of the four states: LISTENING CLOSE_WAIT TIME_WAIT ESTABLISHED What do CLOSE_WAIT and TIME_WAIT mean/indicate?
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0answers
56 views

Name the scope and what layer of the tcp/ip model the following address belong to

For the following addresses, 136.206.11.5 0C:5F:56:C0:DD:08 PORT 80 These are the questions: What is the scope(LAN,internet, machine)? What layer of the TCP/IP 4 layer is the model is involved? ...
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2answers
30 views

Why does a USB Adapter set to monitor mode on Linux not capture non-WiFi traffic send on the same frequency (2.4GHz) as WiFi ?

I have a WiFi Adapter from Alfa that can function in Monitor mode on Linux. Once I set it up and run Wireshark, I am able to see traffic across other routers and devices. If there is a new protocol ...
1
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1answer
27 views

are TCP connections made while typing the URL

Do browsers make TCP connections while typing the URL in address bar? I launched nettop utility, and was surprised of how active my connections are, even while only typing an address and not visiting ...
0
votes
1answer
47 views

Firefox strange connection established, what is this?

I have accidentally found inside Firefox process properties (using Process Explorer) a weird connection in tcp/ip tab: bandicam.com:some_ports it points at localhost 127.0.0.1:some_ports bandicam ...
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2answers
46 views

RST sequence number and window size

RFC793 states the following about RST processing: In all states except SYN-SENT, all reset (RST) segments are validated by checking their SEQ-fields. A reset is valid if its sequence number is ...
9
votes
3answers
11k views

What is “Disable class based route addition” good for?

In the advanced TCP/IP settings of a Windows VPN connection, I found a checkbox labeled Disable class based route addition. The checkbox is only enabled as long as Use default gateway on remote ...
1
vote
1answer
58 views

HP Laserjet 4000T prints PCL XL UnsupportedProtocol error

I have a working CUPS setup, configured for a HP LaserJet 4000T printer. It works fine from all stations, except Windows 10-x64. There is no HP LJ 4000 printer in the list with installable printers, ...
2
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2answers
115 views

Send TCP with incorrect checksums

I'm having trouble sending large files to an OpenStack machine. Our Internet connection is over LTE so bad packets are to be expected. However, even sending data over TCP results in corrupted data ...
0
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0answers
18 views

How do I create a Docker container with a non-default IP address?

I created a docker container with this command: docker run -p x.x.x.x:80:8080 <imageName> bash where x.x.x.x was the IP address of the Docker server running CentOS version 7. I then tried to ...
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0answers
18 views

DHCP-Enabled Router Sometimes Won't Talk to Host with Static IP

I have a Windows 7 host connected to a router running DD-WRT. The router is running a DHCP server. For reasons I don't need to detail here, I have set a static IP on the host, as opposed to ...
0
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0answers
29 views

How to disable TCP Checksum for wireless device in Windows 10?

I want to disable TCP Checksums on my wireless adapter. For ethernet device, I can turn on/off TCP checksum as it can be seen down below; However, for wireless adapter, there is no such an option ...
0
votes
1answer
2k views

What other protocols can run over the Link Layer besides IP protocol?

I am reading about ARP here and it says "Each protocol is assigned a number used in this field. IPv4 is 2048 (0x0800 in Hexa)." What are other alternatives to IPv4 and IPv6 as protocols to be run ...
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1answer
547 views

One or more network protocols is missing on this computer

I just rebooted my Windows 10 PC, tried to connect to the internet and got a message saying "One or more network protocols is missing on this computer". The Windows troubleshooter is unable to fix the ...
0
votes
1answer
34 views

Malware Allowing Remote Access to my Machine

I would like to understand how Malware allows a remote connection to my machine. Am I correct in thinking that my modem / router will block all inbound connections from the internet? A scan has shown ...
0
votes
1answer
41 views

How to get a network of different IP addresses on IPv6?

Does anyone know if it is possible to get a network of different IP addresses on IPv6 (not sure if they have it in my area?). What I'm thinking is maybe I could have a little network like at work now ...
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0answers
166 views

No connection could be made because the target machine actively refused it

On Windows machine, I start a server on port 62325 $ netsh firewall show state shows: Ports currently open on all network interfaces: Port Protocol Version Program -------------------------------...
3
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1answer
79 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 ...
3
votes
3answers
1k views

disabling hyper-v in windows 10 causes complete network failure

I have disabled (uninstalled) Hyper-V so I can run VM-Ware and have completely lost the network. It shows the cable connected but there is no internet connection. Ive tried a different cable and have ...
2
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2answers
175 views

What are the detailed OSI model steps involved in connecting to a website?

What are the detailed steps involved in connecting to a website, such as superuser.com home page using a newly connected computer (http, and nothing cached)? What is actually happening in the ...
0
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1answer
28 views

Listen to localhost messages

Suppose a TCP/IP client application has connected to a certain port on a server. Both client and server are operating on localhost. Is it possible for another application (also on localhost) to ...
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2answers
43 views

what distinguished OSI from TCP/IP in practice?

so i am going through cisco ccent/ccna. working through the text on my own just for general useful knowledge. so in the early part of the book it goes into describing the different layers of the TCP/...
0
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1answer
145 views

Where'd my wireless go?

Got an old Lenovo R60e running XP Home that I use for misc. wireless tasks around the house. I had need to print from a fixed workstation to a USB printer in another room. So, I turned on printer ...
6
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4answers
28k views

Any free application to redirect serial communication to TCP/IP? [closed]

Please can anyone suggest a free application which creates virtual serial ports and any traffic on that port is redirected to given TCP/IP address?
10
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18answers
14k views

Can the Internet work without DNS?

If we have an IP-based system of identifying nodes on the Internet why is there a need for DNS?
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1answer
583 views

VMware Workstation isolating guest to a separate internet

I have N1 and N2 network. The host has two ethernet adapters E1 and E2. The host is connected to N1 through E1, but I want to connect a guest to N2, and I do not want N2 to affect the host by any ...
0
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0answers
63 views

How to simulate TCP simultaneous open and close conditions?

I am learning TCP/IP protocol. I want to see simultaneous open, close, half open/close, etc conditions in practice. I have created simple TCP server and client program. How can I simulate simultaneous ...
6
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4answers
21k views

what is TCP Half Open Connection and TCP half closed connection

I am trying to understand what is the difference between TCP Half Open Connection and TCP Half closed connection can any one tell what exactly are they?
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0answers
79 views

Single TCP retransmission causes 15 seconds delay on wireless

I am having a strange problem which causes long delays in http requests (POST in this case) to my own web server. This occurs only if - a linux or Mac client is used (Windows is fine), and - the ...
1
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1answer
41 views

Ways in Which TCP/IP Stack Fails?

In a variety of books and learning materials, we're told that if pinging the localhost/loopback address fails, this is a sign of a malfunctioning TCP/IP stack. What we aren't told is why/how this may ...
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2answers
53 views

Identify the TCP/IP classes respectively by beginning octets

I am busy studying for a network exam and I am stuck with this zinger: By studying the following beginning octets, identify the TCP/IP classes respectively 1-126 224-239 240-254 ...
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3answers
300 views

Relation between TCP conversations and TCP streams in Wireshark

I have read about Conversations and TCP Streams but I'm still a bit unsure how they relate to each other if they are on the same layer. For different layers, it's clear to me that e.g. an IP ...
10
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1answer
2k views

Why has Microsoft never implemented a loopback interface in Windows?

First things first: I know that you can install a sort-of-a Loopback Adapter in Windows. But what I really found strange is that there exists nothing like lo on Windows. At all. From The missing ...
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0answers
96 views

Laptop can't ping (or see on arp) network printer. All other devices can

I have a small home office network. Two laptops connecting to the router wirelessly and the printer (Sharp MX2301N) is connected to the router by ethernet cable. The Faulty Computer (FC), running ...
0
votes
3answers
629 views

XP to Win 7 via ethernet cable. No routers, no wireless. They can't ping each other

I've got a windows XP machine and a windows 7 laptop connected by an ethernet cable. The xp has static ip address 169.254.84.221 and the windows 7 has 169.254.84.220. both subnet masks 255.255.255.0. ...
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4answers
47k views

How to get a Port to listen on Windows 7?

I have followed the step by step instruction to open a port on Windows 7, setting both Inbound Rules and Outbound Rules to following specification: Protocal Type: TCP Local Port: 55000 Remote Port: ...
0
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0answers
57 views

Kill TCP connection in VMware ESXi 5

If there anyway to kill a tcp "TIME_WAIT" state connection in VMWare ESXi~ # esxcli network ip connection list Proto Recv Q Send Q Local Address Foreign Address State World ID ...
0
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0answers
104 views

Will a WSD Port monitor block the detection of a TCP/IP port?

I have a printer set up on our print server that inadvertently diverted to a WSD port monitor. The intention was for it to be configured pure TCP/IP. When I went to add a local printer and use the IP ...
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9answers
181k views

How to find the MAC address of a remote computer?

I know the IP address of a host on my own LAN. Using that, how can I find its MAC address (without having to physically access it)?
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0answers
1k views

DNS server keeps changing from Auto to Manual

A friend at a company I know has a fairly new Windows 7 laptop. She was complaining that the "internet doesn't work". After looking at it the first time, in Wireless > Status > Properties > ...
2
votes
4answers
26k views

how to enable 'Properties' button of TCP/IPv4 in Network connections in Windows 7

In the Control Panel\Network and Internet\Network Connections, I have a Wireless Network Connection. When I right-click on it, a properties dialog opens. Now, I need to change the IP address for TCP/...