srp is missing response (Centos 5.11)

[goldbaum]

Brief description

Sending a simple TCP SYN packet results in no response according to scapy.

How is decided if a packet is a response to another?

Environment

• Python 3.6.1 (default, Jul 19 2019, 17:04:00)
• Scapy Version 2.4.3
• Linux hostname 2.6.18-398.el5 Windows: use Winpcap, drop DNET dependency #1 SMP Tue Sep 16 20:50:52 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux

How to reproduce

>>> tcp_packet = Ether(src="00:50:56:AF:A8:83", dst="00:50:56:AF:2F:87")/IP(src="101.100.100.66", dst="201.200.0.64")/TCP(sport=333, dport=12345, flags="S")
>>> ans, no_ans = srp(tcp_packet, iface="eth1", timeout=5)
Begin emission:
Finished sending 1 packets.

Received 0 packets, got 0 answers, remaining 1 packets
>>> ans.show()
>>> no_ans.show()
0000 Ether / IP / TCP 101.100.100.66:texar > 201.200.0.64:italk S
>>>

Actual result

• No Answer

Expected result

• Answer

Related resources
scapy_srp_missing_response.pcap.zip

[guedou]

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