May 2018
Intermediate to advanced
326 pages
8h 32m
English
Content preview from Practical Network Scanning
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Time-to-live (TTL)
Based on network traffic between hosts, it is possible to predict what OS is running on a system. Every operating system has its own unique way to implement TCP/IP stack. A very simple but effective passive method is to inspect the initial time-to-live (TTL) in the IP header:
I am on a Windows 10 machine and tried the ICMP ping to host 4.2.2.2. In the Wireshark capture attached below, you can see that the Windows 10 initial TTL value is 128:
I expended the first packet from Wireshark, which confirms TTL 128:
Let's try to ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.