TCP is just one communications protocol on the web. Others include: User Datagram Protocol (UDP) udp Internet Control Message Protocol (ICMP) icmp Hypertext Transfer Protocol (HTTP) http Post Office Protocol (POP3) pop3 File Transfer Protocol (FTP) ftp Internet Message Access Protocol (IMAP) imap ...
0
votes
0answers
10 views
Does change of tcp_keepidle or any of the tcp parameters require a reboot(AIX)?
AIX 5.3
oslevel -r
5300-12
We require to change the tcp_keepidle value using :
no -o <tcp_parameter>= ...
0
votes
2answers
30 views
http ftp imap smtp and some additional ports not working
I'm writing this using a 3G connection on my phone.
At lunch time yesterday, the ports above and a few additional other ports like 40001 and 4089 stopped working on my internet connection at work.
...
2
votes
0answers
30 views
Why is my tcp window size going to zero when using VIM over VPN
I use a mac os laptop over a typical (i.e. crappy) wireless home network and connect to work over a VPN. I ssh into the linux (ubuntu) desktop I have in my office at work. (When I say, "I ssh": I ...
4
votes
1answer
133 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 ...
1
vote
2answers
93 views
Hardware/Software behind IP/TCP layers encapsulation
Every tutorial I read talks about how the layers "communicate" with each other, but never mentions what hardware/software receives, adds on, and sends each layer of control data.
What piece of ...
1
vote
1answer
52 views
Does mobile phones use TCP/IP? [closed]
Does mobile phones (any kind of mobile phone?) use TCP/IP over radio signals for internet? I would also like to know if they use VoIP for telephony? Please tell me what they use, I'm confused.
3
votes
1answer
31 views
DNSSEC regarding
I'm asking this question as software (and also because there have been a few DNSSEC questions on here in the past).
http://en.Wikipedia.org/wiki/DNS_cache_poisoning#Prevention_and_mitigation
I ...
0
votes
1answer
57 views
How to delete binded port from cmd in Windows 7?
How to delete binded port in Windows 7 from cmd? I'm developing client server application which running on the port 3434 and also is binded on port 0.0.0.0. When I type in cmd netstat -an, I get this ...
7
votes
3answers
208 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.
...
1
vote
1answer
75 views
Difference between TCP and IP tunnelling?
Can someone please explain in terms of the OSI (or TCP/IP) layers, what is the difference with what goes on when you tunnel IP or TCP, say over the ICMP protocol (although the latter doesnt really ...
0
votes
2answers
41 views
How do I test the maximum TCP/IP transfer rates of my computer?
In Delphi, I am writing client software for open source message brokers, and would like the transfer rates with a realistic upper limit of what can be achieved on my local computer, or between my ...
-2
votes
1answer
42 views
How does a file is delivered to destination? [closed]
If I send a file using TCP protocol to a destination in some other country how does it get delivered? For example - Looking at the basic OSI Model,
Application
Presentation
Session
Transport
Network
...
0
votes
0answers
58 views
How does SSL-VPN tunneling and encryption work?
I have a few questions on SSL-VPN (Tunnel, not portal version). Question 1 is probably the one I'd like answered the most, out of my four questions.
How exactly does SSL-VPN tunneling work (Feel ...
2
votes
1answer
35 views
SSL/TLS and VPN-SSL?
As I understand it, SSL/TLS is used when we visit a website using https. However, using this method only encrypts the data and not the IP address of the website we're requesting.
If you use a VPN ...
1
vote
1answer
100 views
Can IPSec (or any other VPN tunnel) hide your IP address while browsing?
Is there a VPN/tunnelling method which you can use to browse the web, but will also prevent somebody from seeing your IP address if they were sniffing the network?
I wasn't sure if the IP address ...
0
votes
0answers
34 views
ICMP Tunnelling IP vs Tunnelling TCP?
Could someone please explain the difference between tunnelling IP data using ICMP packets and tunnelling TCP data via ICMP?
Obviously I know this is going to be something relevant to the different ...
2
votes
1answer
86 views
Understanding ipconfig output in Windows
I use Windows 7 and am connected to a LAN. In cmd I typed ipconfig.
There were many headings reading "Tunnel adapter local area connections" (with 13/19/17 appended to it). What does this mean?
...
5
votes
1answer
124 views
Does TCP/UDP send file sequentially or randomnly?
Does TCP/UDP protocol always send or receive file packets sequentially? Would it possible to make a choice which data packets will be sent first using sockets API?
0
votes
2answers
91 views
TCP Window Scale
I am searching that, how can two sides determine which scale factor will be using? In syn packets we can give a scale factor and than when two sides have the any scale factor, we can understand that ...
1
vote
3answers
92 views
How will I know whether my laptop computer is being shared
How will I know whether my laptop computer is being shared through TCP and IP or not been shared? What command should I look or click through? When I click the button bar for Local Area Connection ...
2
votes
2answers
99 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. ...
1
vote
1answer
61 views
Sending a file via TCP/UDP socket
I'm reading about TCP and UDP from a article. In the end what I understood is that UDP is faster than TCP but it is unreliable. So if I'm going to a send a file, If use UDP, would it
be faster than ...
2
votes
3answers
42 views
TCP/IP on the transport level
I'm trying to understand what happens when I send a packet using a socket on the transport level. Do all packets which leave my computer go first to a geographical location designated by my ISP? Then ...
0
votes
2answers
95 views
TCP PUSH and segments
I am reading the TCP PUSH section in the TCP/IP Guide, and have a question on this paragraph:
It's important to realize that the push function only forces immediate delivery of data. It does not ...
0
votes
0answers
51 views
Finding why a TCP connection drops
Two months ago the german Audible shop relaunched their site to be more like their parent company Amazon. Since then I've not been able to download my purchases.
The culprit is my Netgear WGR614v8 ...
0
votes
1answer
29 views
Video player that can be controlled by Socket / TCP
Is there a Video Player that can be controlled with TCP?
I think VLC supports this - but I can't find any easy to follow instructions on how to do this.
I will be using this on a windows 7 machine, ...
0
votes
0answers
30 views
How to interpret NutTCP warning: “IP frags or no data reception since buflen > ctlconnmss”
I'm using NutTCP 5.3.1 to test UDP performance on an IPv6 network.
The server is running on another machine.
This is running under Windows with the supplied Cygwin DLL.
The client command is:
...
0
votes
0answers
23 views
Every new process takes 20 seconds to initiate internet connection
I am using Win 7 x64. Every process that I open (chrome / IE / outlook / etc.) takes about 20 seconds to connect to the internet, but only at the first connection they initiate. It just 'hangs' and ...
0
votes
2answers
148 views
Why can't a PC with 2 network cards be accessed by hostname?
I set up PC with 2 network cards, connected to the same LAN.
I can connect to this PC (e.g. by remote desktop) only via ip-addresses. Accessing by hostname does not work.
Why is this the case?
...
0
votes
1answer
58 views
How to listen to all ports (udp and tcp) or make them all appear open in Debian
I got an external Debian server. The problem is that my university campus doesn't allow connections to go outside when the port is different than TCP port 22, 80, 443, or UDP port 123. I tested them ...
0
votes
0answers
33 views
TCP option in sar returns “Requested activities not available”
I am trying to configure TCP options in sar. I used the following settings in /etc/default/sysstat:
SA1_OPTIONS="-S SNMP"
Still, sar -n TCP says
Requested activities not available ...
Rest ...
8
votes
2answers
145 views
On the Performance of TCP implementations of Linux and Windows
As I understand the implementation of TCP stack in windows and Linux are different. Windows uses a congestion control algorithm known as the TCP Reno while Linux uses Cubic.
How do the 2 protocols ...
1
vote
1answer
49 views
How does the Inetutils telnet utility determine if a connection is still alive?
I've started using sockets in programming with Java (I have experience with Python), and while testing a server that I'd written with the telnet command, I noticed that the utility responds ...
0
votes
2answers
143 views
2
votes
2answers
238 views
Windows TCP timeout
Is there on windows any default timeout for tcp connection? So when no answere is received the connection would be closed.
Why im asking is that on one machine the connection is closed afther 5 ...
3
votes
1answer
82 views
Where do I find the TCP/IP stack in Process Explorer on Windows 7?
I was wondering, if the TCP/IP stack is part of the kernel or running as a service? Where do I find the TCP/IP stack in sysinternals ProcExp?
1
vote
0answers
72 views
Create VNC Proxy with authentication
We have a bunch of VNC servers located on our local network. We wish to give external customers access to these VNC servers, via some sort of "middle-man" software solution which can handle ...
2
votes
2answers
59 views
What is the difference between SOCKS4/5 and a pure TCP proxy?
Why do we need SOCKS if we could just use a TCP proxy system like TOR? What kind of advantages does SOCKS have?
1
vote
0answers
59 views
Is there a software that allows RS232 sniffing and TCP/UDP listening
I am looking for a software that would fulfill the following requirements:
Able to "sniff" communication over RS232 (like PortMon and Advanced Serial Data Logger)
Able to listen to a given ...
2
votes
3answers
177 views
Linux Command Line Tools for Analyzing OS + NIC TCP Latency
I'm hoping to find an existing Linux tool for measuring latency:
I'm trying to diagnose how much latency my OS and NIC card are adding to TCP latency in Linux. I looked at the following tools but ...
1
vote
1answer
63 views
Can't access HTTP server, but ping works in LAN
I encounter a problem when configure the connection. My computer resides in a LAN, I want to assign it a static IP address.
Thus with the help of port mapping on the router, I will be able to access ...
0
votes
2answers
128 views
How does Ident work?
I am having a hard time understanding how ident works. I came across a summary of how it works at Wikipedia however don't quite follow what it means
The Ident Protocol is designed to work as a server ...
3
votes
1answer
100 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
votes
1answer
666 views
How to change TCP “time wait” delay in Windows 7 / 2008 Server?
Windows Server 2003 "offers two methods of controlling TIME-WAIT behavior."
The TcpTimedWaitDelay registry value under the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters ...
1
vote
2answers
119 views
How do I redirect a request for an IP to the loopback?
A program I'm using makes a request for the external IP 74.125.234.83 and I would like to make this request redirect to 127.0.0.1 so I can test my local server, I don't have access to the source of ...
0
votes
5answers
145 views
How does a router route connections?
How does a router track connections? When you send a http request it goes to the router which is then sent to another router, etc over the internet; but then how does it know to go to the server, is ...
0
votes
1answer
150 views
Ubuntu Server static Route through ubuntu PC
Working my way through understanding Linux.
I still consider myself a newbie. I recently installed a 10.04 server with LAMP and others on it. I wish to get it surfing the net: apt-get update and ...
1
vote
0answers
99 views
iodine fails its ping test
I'm trying to get iodine working on my Ubuntu machine.
The server is working fine, but when it try to establish a connection, and change the route table using the default iodine-client-start script i ...
0
votes
2answers
80 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 ...
1
vote
1answer
199 views
How to make tcpdump (or other tool) to actually dump TCP stream?
I expect something like this:
$ nc example.com 80
GET / HTTP/1.0
HTTP/1.0 500 K.O.
Content-Type: application/null
Content-Length: -1
$
Meanwhile:
# tcpdump -i eth0 --actually-dump-all-tcp
...
