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.
6
votes
9answers
4k views
Why is IP to MAC address translation needed?
On networks that use the TCP/IP protocol, why is the IP address translated into a MAC address?
I mean, when every device knows its IP, why further use the MAC address and not use the IP number as ...
4
votes
3answers
730 views
How to get started with TCP/IP v6?
Now and then there is "news" about that the IP numbers will run out in X years,
and we must change to TCP/IP v6...
And even though this crisis never really happens it has waken a question,
how do ...
2
votes
3answers
2k views
Access Windows from Mac via Remote Dekstop Connection using hostname
I'm using Snow Leopard with Remote Desktop Connection attempting to access a Windows XP machine on a home network. If I specify the Windows PC's hostname it won't connect. Only by specifying the IP ...
2
votes
2answers
5k views
What does this UDP Packet mean?
I'm total newbie at tcp/ip and I was experimenting with Wireshark.
What this mean:
1824 578.194204 xxx.xxx.xxx.xxx yyy.yyy.yyy.yyy UDP Source port: 17500 Destination port: 17500
In data I ...
4
votes
2answers
1k views
Is there a tool to modify HTTP packet on the fly?
Wireshark is good, but it doesn't allow you to change the content of the packet.
Is there a tool to do this job?
0
votes
5answers
592 views
Too many connections to 212.192.255.240
Recently my Internet slowed down drastically. I downloaded a tool to see the TCP/IP connections from my Vista computer. I found that a lot of TCP/IP connections are being made to 212.192.255.240 ...
2
votes
4answers
590 views
Is there any SMS/MMS server for LAN environment
I am looking for a solution to send SMS/MMS message to mobile device from desktop or browser in LAN environment. As such, it is most probably using TCP/IP protocol to transmit request/response.
The ...
1
vote
0answers
379 views
How to choose which network connection provides the default gateway in Windows XP [duplicate]
Possible Duplicate:
How can I change the binding order of network adapters in Windows 7?
I have a laptop with an integrated NIC and a WiFi connection. Both the wired and wireless networks I ...
1
vote
7answers
2k views
In linux, how can I get my IP address - ifconfig and ip addr show are not working
This should be simple, but the machines we ssh into don't seem to have the regular commands.
Are there any other simple ways I can use to get my IP?
1
vote
2answers
238 views
Is it possible to know which process opened a connection in Windows?
With netstat -a I can see all connections from my machine to the MySQL Server.
There is any way too see which process or executable is responsible for each connection?
The only solution I found so ...
1
vote
3answers
2k views
How do the routers communicate with each other?
Let's say that i want make a request a to a web page which is hosted in Europe (i live in USA).My packets only consist the IP address of the web page, first the domain name to ip address ...
0
votes
1answer
5k views
TCP/IP Forwarding in Windows Vista and Above
This is the way to do it on XP, but is it possible on Windows Vista and Above?
If so how do you detect it? Is there a registry setting for it, or is there com dll or api for it?
0
votes
1answer
2k views
Yahoo Messenger IP range
I use PeerBlock (former PeerGuardian) and, as a consequence, Yahoo Messenger (actually Pidgin) fails to connect every once in a while; PeerBlock reports the access being blocked because the ...
4
votes
1answer
3k 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?
6
votes
6answers
4k views
Why is my router not routing?
Starting a week and half ago my router stopped working with my cable modem. I went to sleep with it working and woke up with it not. I swapped in another router and am still having issues; I was ...
0
votes
1answer
350 views
Is it possible to just deny download from TCP/IP?
I want to deny my Internet connection's download properties for all ports. I mean I want to only allow upload. Is it possible?
7
votes
2answers
6k views
What is “Disable class based route addition” good for?
In the advanced TCP/IP settings of a VPN connection, i found a checkbox labeled with "Disable class based route addition". The checkbox is only enabled as long as "Use default gateway on remote ...
5
votes
3answers
630 views
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 ...
1
vote
1answer
484 views
retransmission of lost TCP segment
What will happen in the following scenario (assume the connection is already established):
(stack A) send 10 byte data
(stack B) send ACK for 10 byte data
(stack B) send 200 byte data
(stack B) send ...
6
votes
1answer
2k views
Is your MAC address revealed when you hit up a website?
When you hit up a site, such as cnn.com, does the TCP/IP packet contain the MAC address of your network card?
Could cnn.com theoretically record my MAC address?
3
votes
1answer
2k views
How to enable “packet forwarding” in Mac OS x
How is it possible to enable packet forwarding in Mac OS X?
Google gives me tons of hints for Windows and Linux but not for OS X.
1
vote
1answer
125 views
workstation 7 and host-only no connectivity
I have a WinXP 32 host (IBM T400) with VWware workstation 7 (7.0.1 build-227600) and some guest OS (Win xp, NT, etc.)
I can ping from the host to guest OS and vice versa, but... every other ...
0
votes
3answers
2k views
How do I see which processes have open TCP/IP ports in Mac OS X?
How do I see which processes have open TCP/IP ports in Mac OS X?
4
votes
1answer
263 views
Why does MacOSX try to resolve zero padded IP addresses as host names?
This one caused a friend some headache when setting up a switched internet connection which had zero padded IP addresses in the configuration paper like so:
192.168.019.254
No matter how he tried to ...
0
votes
1answer
85 views
How would I do this in wireshark?
I have four packets captured in wireshark. ARP request and reply packets and ICMP packets. What field and values are used to identify the different packets carried by an ethernet frame?
-1
votes
1answer
931 views
DHCP not working after NetBIOS over TCP/IP disabled
I want to disable the "NetBIOS over TCP/IP" device in the device manager to free port 445. But after doing that my Internet stops working. I'm connected to a WLan router using DHCP on WinXP, and it is ...
1
vote
3answers
682 views
IPv4 forward on windows?
Is there anything that can forward/redirect all incoming traffic to another ip. Basically I'm looking the windows equivalent of ip forwarding in linux.
echo "1" > /proc/sys/net/ipv4/ip_foward
1
vote
3answers
824 views
Switching between DNS addresses easily
Sometimes I need to use preferred and alternate DNS server addresses, and sometimes I need Windows to obtain it automatically. The common approach to switch between those addresses is:
Right click ...
1
vote
5answers
302 views
Only browser causes BSOD — all other TCP operations okay
A few weeks ago I started getting BSODs -- mostly in TCPIP.SYS, but occassionally Memory Parity.
I had some viruses which are now all removed.
I got new memory -- didn't fix it.
Over time I was ...
5
votes
2answers
666 views
Poor TCP performance over single connection, but not over multiple?
On two separate Dell machines, I seem to be having an annoying performance problem when downloading over a single connection. The one I've just tested this all on is a Dell Dimension 3000, XP SP3, P4 ...
10
votes
7answers
6k views
Why is it bad to have open ports?
Here's something that has always baffled me. Why is it bad to have open ports on your computer? Assuming you don't have a virus on your computer or some other program listening to a port that may ...
1
vote
2answers
813 views
Wireless network connection keep dropping
After reinstalling windows XP on my laptop, I've noticed that about ever 3 mins, my wireless network connection will disconnect and then reconnect. I found the following error in the system event ...
1
vote
3answers
590 views
OpenDNS name servers
I'm using the below open DNS name servers which I got from a friend. Are they trustable?
4.2.2.1, 4.2.2.2, 4.2.2.3, 4.2.2.4, 4.2.2.5, 4.2.2.6
2
votes
1answer
820 views
Smokeping monitoring IP address and port
I have successfully install smokeping on my Ubuntu Karmic machine and am monitoring servers.
I need to be able to monitor an IP address and a port, can someone tell me how I do that?
I looked into ...
2
votes
6answers
3k views
Why does my XP system lose TCP/IP connectivity every night around 3 AM?
Every night around 3 AM from the eventlog (Outlook complains it can't get to the exchange server) I lose all TCP/IP connectivity from my desktop. Other systems on the network still function, as well ...
1
vote
4answers
670 views
A can ping B, B can ping C but A cant ping C. How do i connect A to C (ethernet)?
I have a computer at home with ip 192.168.221.xxx
I have another computer at work that I can ping and it has 2 ip addresses: 192.168.1.xxx and 192.168.0.xxx. Those last 2 addresses have the same ...
2
votes
2answers
2k views
Is there a command line way to show the outward-facing IP address for my machine?
Is there a command line way to show the outward-facing IP address for my machine?
2
votes
3answers
3k views
Does using OpenDNS have any disadvantages?
I live in Istanbul and loads of websites are banned here by the government. In order to be able to enter the banned sites like YouTube, some of my friends are using a specific DNS server address ...
3
votes
3answers
5k views
Any free application to redirect serial communication to TCP/IP?
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?
1
vote
1answer
961 views
TCP timeout after one minute
Little background: before going on a business trip I installed all the corporate updates on my winxp laptop (not a great idea). One of them included a new vpn client which might have something to do ...
3
votes
6answers
1k views
Editing the HOSTS file
I'm looking to edit the Windows TCP/IP hosts file (at c:\windows\system32\drivers\etc\hosts). I'm wondering, what is the best way to do this (WinXP)?
Let's say that I want to redirect, say, the site ...
3
votes
2answers
392 views
TCP Checksum, why?
Why does TCP need a checksum, when lower layers do integrity checks anyways (like Ethernet CRC)?
1
vote
2answers
2k views
utorrent stops internet traffic
this is a new problem for me, and I really don't know how to fix it.
From time to time i'm using uTorrent for file transfers, but in the past month when i start utorrent, i cannot navigate anymore ...
2
votes
2answers
881 views
Linux Kernel Packet Forwarding Performance
I've been using a Linux box as a router for some time now. Nothing too fancy, just enabling forwarding in the kernel, turning on masquerading, and setting up iptables to poke a few holes in the ...
12
votes
7answers
11k views
Is there any benefit to using IPv6 on my home network?
I know that IPv6 is the future because there is only 4 billion IPv4 address, but on a home network, you are not going to have 4 billion users. So are there any other benefits that would make IPv6 on a ...
4
votes
2answers
227 views
Prevent a download to saturate all bandwidth on Linux
In Linux, a single download can use all available bandwidth, so that any other connection can't be started. (e.g. if I am downloading updates, I can't surf the web at the same time)
Is there a way to ...
1
vote
4answers
3k views
WinXP with two LAN cards: Howto route only port 3389 onto one LAN card?
I have a Windows XP machine in remote location on which I need to debug an application.
It has two LAN cards both with internet access on different subnets.
Problem is related to LAN card A.
How ...
1
vote
3answers
467 views
Which tool can be used to connect two TCP/IP servers?
The tool should connect to any two TCP/IP servers and transparently route sends and receives between them. The tool should connect to both the TCP/IP servers and transparently forward any data it ...
6
votes
5answers
31k views
How to tell what MTU is being used in Windows XP
I'm suffering from a really weird problem where I randomly get "The connection to the server was reset" errors when trying to access web pages (HTTP error 12031 according to the Windows network ...
1
vote
1answer
107 views
Detecting proxy server from client side
I suspect my ISP is using a proxy server, though I cannot prove it.
The only evidence I've got is that incoming packets have a very high TTL > 254.
Is there a way to check it out, without calling my ...
