Snort Struggles: How to detect the FTP service name?
I am muddling through learning Snort and feeling a bit daft. I'm trying to write a rule that allows me to detect the FTP service name used in a .pcap.
I analyzed the .pcap with
sudo snort -c local.rules -A full -l . -r ftp-png-gif.pcap
I looked up some ways to find the ftp service name and I found a few like sudo snort -r snort.log.1671731339 -X -n 10
which would probably do the trick, but I'm not sure why. I get that -X has something do the preprocessor, but I'm not sure why this outputs anything with FTP, or how to find where the FTP service name is in the output.2 Replies
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UPDATE:
I used the
sudo snort -r snort.log.1671731339 -X -n 10
command and got results for the 10 packets that look like this. As you can see, I found a packet that said 220 Microsoft FTP Service
, but I still don't know why this worked or how they knew the answer would be within 10 packets of the log.![No description](https://cdn.answeroverflow.com/1138903697578020874/image.png)