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| 1 | + | # tcpdump | |
| 2 | + | ||
| 3 | + | * capture HTTPS ClientHello packets and use tshark to extract Hostnames: | |
| 4 | + | ||
| 5 | + | ``` | |
| 6 | + | tcpdump "tcp port 443 and (tcp[((tcp[12] & 0xf0) >>2)] = 0x16) && (tcp[((tcp[12] & 0xf0) >>2)+5] = 0x01)" -w output.pcap | |
| 7 | + | ||
| 8 | + | tshark -r output.pcap -Tfields -e tls.handshake.extensions_server_name -Y 'tls.handshake.extension.type == 0' | sort | uniq | |
| 9 | + | ``` | |
| 10 | + | ||
| 11 | + | * capture HTTP (80) traffic and print headers | |
| 12 | + | ||
| 13 | + | ``` | |
| 14 | + | tcpdump -A -s 10240 'tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)' | egrep --line-buffered "^........(GET |HTTP\/|POST |HEAD )|^[A-Za-z0-9-]+: " | sed -r 's/^........(GET |HTTP\/|POST |HEAD )/\n\1/g' | |
| 15 | + | ``` | |
| 16 | + | ||
| 17 | + | * filter packets with a TTL less than 32 (TTL is the 8th byte in the header): | |
| 18 | + | ||
| 19 | + | ``` | |
| 20 | + | tcpdump -v ip and 'ip[8]<32' | |
| 21 | + | ``` | |
| 22 | + | ||
| 23 | + | * summarise IPs from a pcap: | |
| 24 | + | ||
| 25 | + | ``` | |
| 26 | + | tcpdump -ntr file.pcap | awk '{print $2}' | tr . ' ' | awk '{print $1"."$2"."$3"."$4}' | sort | uniq -c | awk ' {print $2}' | |
| 27 | + | ``` | |
| 28 | + | ||
| 29 | + | * summarise IPs from a pcap (with packet count per IP): | |
| 30 | + | ||
| 31 | + | ```tcpdump | |
| 32 | + | ``` | |
| 33 | + | ||
| 34 | + | ## capture traffic encapsulated IPIP traffic based on IP address | |
| 35 | + | ||
| 36 | + | * first convert the IP to hex [here](https://www.browserling.com/tools/ip-to-hex) | |
| 37 | + | * then run: | |
| 38 | + | ||
| 39 | + | ``` | |
| 40 | + | tcpdump -l ip[32:4] = 0x0a6fc802 or ip[36:4] = 0x0a6fc802” | |
| 41 | + | ``` | |
| 42 | + | ||
| 43 | + | ## capture traffic and send it to a remote location: | |
| 44 | + | ||
| 45 | + | * listen on port 12345 on the remote: | |
| 46 | + | ||
| 47 | + | ``` | |
| 48 | + | nc -l -p 12345 > /home/user/somefile.pcap | |
| 49 | + | ``` | |
| 50 | + | ||
| 51 | + | * tcpdump and pipe it to the remote with netcat (or nc): | |
| 52 | + | ||
| 53 | + | ``` | |
| 54 | + | # nc | |
| 55 | + | ||
| 56 | + | tcpdump -n -U -s 0 -i <interface> not port 12345 -w - | nc <remote IP> 12345 | |
| 57 | + | ||
| 58 | + | # ncat | |
| 59 | + | ||
| 60 | + | tcpdump -n -U -s 0 -i <interface> not port 12345 -w - | ncat <remote IP> 12345 | |
| 61 | + | ``` | |
simon revised this gist 1 month ago · 105e352
1 file changed, 61 insertions