Archive for networking

TTCP

January 10, 2007 at 2:00 am · Filed under networking

The Story of the TTCP Program

nmap, ttcp, netstat, ipconfig all very useful. ping, too.

Yeah, so anyway, this ttcp thing; you set up transmitter and a receiver on the two machines you want to monitor. read about it here.

excerpt from that link:

Starting A PCATTCP Transmitter

To start the PCATTCP transmitter, go to the Command Prompt and then change to the folder containing the PCATTCP.EXE application. Enter the following command:

C:> pcattcp -t 172.16.1.10

The "-t" command-line option starts the PCATTCP program as a transmitter. You must enter the IP address of the platform hosting the PCATTCP receiver after the "-t" command-line parameter.

As soon as you start the PCATTCP transmitter, the test data transfer begins. After the transfer is complete, both the PCATTCP transmitter and receiver will display performance information and then exit. Here is an illustration of what would be displayed:

On The PCATTCP Receiver: C:> pcattcp -r PCAUSA Test TCP Utility V2.01.01.03 TCP Receive Test Local Host : twoeye400 ************** Listening...: On port 5001 Accept : TCP < - 192.168.1.105:1548 Buffer Size : 8192; Alignment: 16384/0 Receive Mode: Sinking (discarding) Data Statistics : TCP <- 192.168.1.105:1548 16777216 bytes in 33.77 real seconds = 485.22 KB/sec +++ numCalls: 2051; msec/call: 16.86; calls/sec: 60.74 On The PCATTCP Transmitter: C:> pcattcp -t 172.16.1.10 PCAUSA Test TCP Utility V2.01.01.03 TCP Transmit Test Transmit : TCP -> 192.168.1.101:5001 Buffer Size : 8192; Alignment: 16384/0 TCP_NODELAY : DISABLED (0) Connect : Connected to 192.168.1.101:5001 Send Mode : Send Pattern; Number of Buffers: 2048 Statistics : TCP -> 192.168.1.101:5001 16777216 bytes in 1.75 real seconds = 9362.29 KB/sec +++ numCalls: 2048; msec/call: 0.88; calls/sec: 1170.29

Comments

more on nmap

September 26, 2006 at 10:30 pm · Filed under networking

You can see what happens if you look for hosts on an address range.

try this:

dig www.number-10.gov.uk

and youll get

www.number-10.gov.uk. 6138 IN A 194.201.189.210

so what else is on the 194.201.189 block?

nmap -sL 194.201.189.0/24

or, to capture to a file:

nmap sL 194.201.189.0/24 -oN btdowningstreet

and youll see theres another government site next door.

nmap -A -T4 194.201.189.210

will show you that its running on windows and http is the only port open.

Anyway, so whats the point of this? If youre about to buy some hosting, you can see what sort of scale your prospective host is at. Have they bought a block if ip numbers from a larger provider or do they own the entire address space? Are they giving you an ip number in the same area as their own business site or are they selling you somewhere else? What machine is there? Whats the setup? Forewarned is forearmed.

Comments

Is your broadband secure?

September 26, 2006 at 9:00 pm · Filed under networking

If you run a program called nmap you can find how secure is your home/office setup.

Once youve installed, find out your ip address and run this:

nmap -sP [your ip address]

see what happens. this sends a ping to your computer and your computer should not respond. if it does, try this:

nmap -A -T4 [your ip address]

Now, this will see what ports you have open.

If you have your machine is closed to pings, try this:

nmap -P0 (thats a zero) [your ip address]

and see what happens. you may well have to ok some prompt from your firewall.

This technique is known as port-scanning. I wouldnt make too much of a habit of it, but a now and then go at it will allow you to show it as a justifyable part of a security audit.

You want to know how safe you are, right?

So, give it a go. You maybe surprised with the results.

Comments