TCP stands for Transmission Control Protocol and is one of the core protocols of the Internet Protocol Suite. TCP complements the Internet Protocol (IP), and therefore the entire suite is commonly referred to as TCP/IP.

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21
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3answers
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How does Router know where to forward packet

If several computers with local addresses (192.168.0.#) are connected to a router and each computer opens a web browser and requests a page over HTTP, when these TCP:80 packets are sent out, the ...
20
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4answers
51k views

What does “On-link” mean on the result of “route print” command?

I'm using Windows 7. When I type "route print" under command prompt, I get a IPv4 Route Table with several "On-link" values under the Gateway column. For example, like this one: IPv4 Route Table ...
5
votes
3answers
9k views

How exactly does a proxy work?

If I want to connect to say, IP 100.100.100.100, Port 80, my computer will send a tcp packet with this adress into the wire. Now If I use a proxy server say, 200.200.200.200 Port 8080 (such kind of ...
9
votes
2answers
3k views

Do browsers create new TCP connections for each HTTP requests?

So I know that HTTP is basically just a text protocol over TCP, and that TCP is state / connection based. That means that the browser has to connect over TCP to a server before doing an HTTP request. ...
3
votes
1answer
400 views

Why small TCP connections succeeds, but big ones fails?

Sometimes from Linux system I see the following weird behaviour: I able to ping things and sometimes use some services, but networking is very bad. For example, now I routed connection through my ...
0
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2answers
4k views

Examine open TCP connections on Mac

What is the Mac equivalent of TCPView or CurrPorts? I've never used Mac before, so I'm clueless.
16
votes
5answers
8k views

Ethernet vs TCP vs IP?

What is the difference between Ethernet, TCP, and IP in simple (simple abstract) terms? Please do not copy from Wikipedia...
6
votes
5answers
9k views

How do IP answer packets reach their destination inside of a private LAN?

This is a little theory question that has been confusing me for a pretty long time. Basically, if we are inside of a private LAN, and we want incoming packets to reach, for example, an HTTP server ...
8
votes
1answer
3k views

Why Windows 7 / PuTTY drop TCP connections even on very brief outages?

I have a small local network that piggybacks on a captive WiFi, and I use ssh on OS X with -oServerAliveInterval=240 and PuTTY 0.62 on Windows 7 Professional for establishing connections to my Linode, ...
7
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2answers
10k views

How does circumventing IP restrictions through DNS work in the case of hulu.com?

I just heard from an australian guy that it is possible to watch hulu.com from Australia (which is actually restricted by country IP checks) by using certain DNS servers. Now I was wondering, how ...
9
votes
3answers
1k views

What do the numbers used in a IPV6 address mean?

I am trying to understand IPV6. I have a server with the following IPV6 address: 2607:f750:0:3f::f59. I don't understand what the numbers mean. It looks totally different from an IPV4 address. ...
3
votes
1answer
5k views

Remotely push DNS server to client via OpenVPN

When I try to push a DNS server via the OpenVPN server-config I don't get that server to be the first DNS server on the connected client system. It ends up being specified as an alternative DNS ...
0
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2answers
532 views

Understanding port forwarding and NAT

I've got some confusion about port forwarding vs NAT. I know the problems NAT causes for P2P, and that there exist some solutions to it (STUN,TURN,etc) which require a relay server to setup direct ...
0
votes
1answer
516 views

How do I establish a connection between 2 computers on different subnetworks?

computer A(192.168.1.134) needs to establish a UDP connection to computer C(192.168.0.30). As you can see both are on a different subnetwork. Now I have computer B which has 2 IP addresses, one for ...
8
votes
6answers
5k views

Port scan revealed port 1111 open. What is it?

I am new to systems administration and have a new server running a website with http (at port 80), https (at port 443) and ssh (at port 22). I did an nmap port scan using my personal laptop and other ...
4
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1answer
1k views

What is the purpose of ports?

I have a few questions in regard to the following explanation of ports I found. The Application layer talks to the Transport layer through a port. Ports are numbered and standard ...
2
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5answers
25k views

Inbound TCP connection limit in Windows 7

I've done a bit of searching on the internet trying to find out whether there is an INBOUND TCP connection limit on Windows 7. We're writing a server product which processes data from a number of ...
1
vote
1answer
55 views

is it possible to update tcp window scaling factor after 3-way handshake by sending a syn/ack?

tcp window scaling factor is notified during 3-way handshake period is it possible to update tcp window scaling factor after 3-way handshake for example, by sending a SYN/ACK with tcp header option ...
1
vote
1answer
4k views

How to set TCP/IP abort interval or timeout in Windows XP?

Does anyone know how to set the TCP/IP abort interval or timeout in Windows XP? In my machine, when I open http://129.129.129.129 in IE, Firefox, or Google Chrome, it will cost about 20 seconds to ...
0
votes
1answer
287 views

How can I detect long-lived connections and mark them for shaping

I would like to detect TCP connections which have been open for more than one minute (or for greater than N bytes, or M packets), so I can classify them as bulk traffic ("downloads") and de-prioritise ...
0
votes
2answers
177 views

If there are 2 NICs on the same machine, can a TCP client on one NIC connect to a TCP server on the other NIC?

I use TUN/TAP to create a tun NIC tun0 with IP 10.10.10.2, and I have a real NIC eth0 with IP 202.112.34.49 Then I run a TCP client which binds its socket to 202.112.34.49 and a TCP server binding ...
0
votes
2answers
5k views

Minimum size of the data part of TCP segment

My question has two parts: I know that the "data" part of an Ethernet frame can be 46~1500 bytes. Considering the IP header of 20 bytes + TCP header of 20 bytes, the minimum "data" size of a TCP ...