BACKTRACK 5 R3 : 0trace

This post is going to introduce you to a "Identify Live Hosts" tool by the name of 0trace that enables a user to perform hop enumeration (“traceroute”) within an established TCP connection, such as a HTTP or SMTP session. This is opposed to sending stray packets, as traceroute-type tools usually do. The important benefit of using an established connection and matching TCP packets to send a TTL-based probe is that such traffic is happily allowed through by many stateful firewalls and other defenses without further inspection (since it is related to an entry in the connection table).

How to reach 0trace ?

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The command syntax :

root@bt:/pentest/enumeration/0trace# ./0trace.sh eth0 (IP ADDRESS1)

and then you need to then open another terminal and connect using netcat as below

root@bt:~# nc (IP ADDRESS1) 80

Here in the example as shown vide screenshots,i have used a web site ip address for sample check....without opening the second terminal window...you will not get any progress on the first terminal....

Finding Maximum frame size on the Network : PING makes it easy

1.   We know how to get the IP address of any website...we simply need to ping it.For example if we need to know the IP address of a website ie www.somesite****.com...then we only need to ping it....like shown in the screen shot below :

2.   So we get the IP address of the web site at www.somesite****.com as *.*.*.*....But if we need to know the maximum frame size that this can handle...what's the way out ?...ping will be able to assist us here too...we need to add some switches to it...so the next command goes like :

ping www.somesite****.com -f -l 1500 and we get this as the output :

3.   The display Packet needs to be fragmented but DF set means that the frame is too large to be on the network and needs to be fragmented.Since the -f switch is used,the packet was not sent and the ping command returned with this error.

4.   Now instead of 1500...type the same command with the attrib as 1300 like ping www.somesite****.com -f -l 1300

5.   So here we have got a bracket of size ie the maximum packet size is more than 1300 and less then 1500 bytes...so keep trying with values between 1300 and 1500 till ur reach the exact breaking point wherein the message in the ping display changes...so here the border line at which the message changes is shown in the screen shots below :

6.   So for the given www.somesite****.com ,the maximum frame size on the machine network is 1472 bytes....

7.  If you wanna try this in your network,then the 1300-1500 set that I have used may be different...so first you need to figure out those boundaries yourself!!!!!