tcpdump cannot filter based upon the content of the packets (no deep packet inspection) as it only uses pcacp-filter.
You could improve your performance by only dumping those packages for incoming TCP connections to your HTTP port.
tcpdump - i lo - A tcp port 80you can use scapy the sniff function and use regex or grep
import scapy
tcpdump = sniff(count = 5, filter = "host 64.233.167.99", prn = lambda x: x.summary())
print tcpdumpor maybe you want to save the traffic and see it in wireshark
wrpcap("temp.cap", pkts)Is it ethically justifiable to conceal a fatal conceptual flaw in a thesis to avoid an unaffordable 2-year setback if the flaw is the advisor's fault? ,You may need to increase the snaplength with "-s" to fully show the packet, also. Something like "tcpdump -A -s 1500" with the filter options., How can I match text at the beginning of a line and print the X previous lines along with the matched one? ,I'm not sure about the available options in Windump, but on tcpdump on Linux, you have:
I'm not sure about the available options in Windump, but on tcpdump on Linux, you have:
-A Print each packet(minus its link level header) in ASCII.Handy
for capturing web pages.I prefer to capture everything in a file like this:
tcpdump - X - s0 - w / tmp / wtf capture_parameters_go_here
Created/Updated: June 9, 2021
04: 45: 40.573686 IP 78.149 .209 .110 .27782 > 172.30 .0 .144 .443: Flags[.], ack
278239097, win 28, options[nop, nop, TS val 939752277 ecr 1208058112], length 0
0x0000: 4500 0034 0014 0000 2e06 c005 4e8 e d16e E. .4........N..n
0x0010: ac1e 0090 6 c86 01 bb 8e0 a b73e 1095 9779....l...... > ...y
0x0020: 8010 001 c d202 0000 0101 080 a 3803 7 b55............8. {
U
0x0030: 4801 8100This page was last updated on Jun 29 2022.
# tcpdump - ni igb1 - c 5
tcpdump: verbose output suppressed, use - v or - vv
for full protocol decode
listening on igb1, link - type EN10MB(Ethernet), capture size 96 bytes
23: 18: 15.830706 IP 10.0 .64 .210 .22 > 10.0 .64 .15 .1395: P 2023587125: 2023587241(116)
ack 2091089207 win 65535
23: 18: 15.830851 IP 10.0 .64 .210 .22 > 10.0 .64 .15 .1395: P 116: 232(116) ack 1 win 65535
23: 18: 15.831256 IP 10.0 .64 .15 .1395 > 10.0 .64 .210 .22: .ack 116 win 65299
23: 18: 15.839834 IP 10.0 .64 .3 > 224.0 .0 .18: VRRPv2, Advertisement, vrid 4, prio 0,
authtype none, intvl 1 s, length 36
23: 18: 16.006407 IP 10.0 .64 .15 .1395 > 10.0 .64 .210 .22: .ack 232 win 65183
5 packets captured# tcpdump - ni igb1 - e - c 5
tcpdump: verbose output suppressed, use - v or - vv
for full protocol decode
listening on igb1, link - type EN10MB(Ethernet), capture size 96 bytes
23: 30: 05.914958 00: 0 c: 29: 0b: c3: ed > 00: 13: d4: f7: 73: d2, ethertype IPv4(0x0800), length 170:
10.0 .64 .210 .22 > 10.0 .64 .15 .1395: P 2023592509: 2023592625(116) ack 2091091355 win 65535
23: 30: 05.915110 00: 0 c: 29: 0b: c3: ed > 00: 13: d4: f7: 73: d2, ethertype IPv4(0x0800), length 170:
10.0 .64 .210 .22 > 10.0 .64 .15 .1395: P 116: 232(116) ack 1 win 65535
23: 30: 05.915396 00: 13: d4: f7: 73: d2 > 00: 0 c: 29: 0b: c3: ed, ethertype IPv4(0x0800), length 60:
10.0 .64 .15 .1395 > 10.0 .64 .210 .22: .ack 116 win 65299
23: 30: 05.973359 00: 00: 5 e: 00: 01: 04 > 01: 00: 5 e: 00: 00: 12, ethertype IPv4(0x0800), length 70:
10.0 .64 .3 > 224.0 .0 .18: VRRPv2, Advertisement, vrid 4, prio 0, authtype none, intvl 1 s,
length 36
23: 30: 06.065200 00: 13: d4: f7: 73: d2 > 00: 0 c: 29: 0b: c3: ed, ethertype IPv4(0x0800), length 60:
10.0 .64 .15 .1395 > 10.0 .64 .210 .22: .ack 232 win 65183
5 packets captured# tcpdump - ni igb1 host 192.168 .1 .100
# tcpdump - ni igb1 src host 192.168 .1 .100# tcpdump - ni igb1 dst host 192.168 .1 .100
# tcpdump - ni igb1 src net 172.16 .0 .0 / 12I'm using tcpdump for some tests I want to see the IP and port number but the output of tcpdump is like,Add -n to your tcpdump command line. ,It should also be noted that on Fedora (and perhaps other derivatives: RHEL, CentOS, etc.) they have patched the original tcpdump version to include a separate option -nn to remove port numbers. From the manpage:,so is it possible to how to make tcpdump to display ip and port number but not hostname and protocol if so , how? thanks
From the tcpdump manpage:
-n Don 't convert addresses (i.e., host addresses, port numbers, etc.) to names.
It should also be noted that on Fedora (and perhaps other derivatives: RHEL, CentOS, etc.) they have patched the original tcpdump version to include a separate option -nn to remove port numbers. From the manpage:
-n Don 't convert host addresses to names. This can be used to avoid DNS lookups. - nn Don 't convert protocol and port numbers etc. to names either.
Run it as:
tcpdump - nn
I think the best approach is:
sudo tcpdump - ni any
Open a console and type:
sudo nc - l - p 6666Open another console and type:
sudo tcpdump - ni any
Expected output:
10: 37: 13.770997 IP 127.0 .0 .1 .56920 > 127.0 .0 .1 .443: Flags[S], seq 2822288041, win 43690, options[mss 65495, sackOK, TS val 1028779 ecr 0, nop, wscale 7], length 0
If you use sudo tcpdump -i any you will see something like this:
10: 38: 22.106022 IP localhost .56924 > localhost.https: Flags[S], seq 3147104744, win 43690, options[mss 65495, sackOK, TS val 1045863 ecr 0, nop, wscale 7], length 0
Open a console and type:
sudo nc - l - p 6666Open another console and type:
sudo tcpdump - ni any
Open a third console and type:
telnet localhost 6666