bug on sr function

[giovanni-bellini-argo]

Brief description

i'm trying to make some netbios queryes to do an host discovery and when querying an host sr returns no answers even tho wireshark says otherwise, i compared the answers of both working (with socket module) and non working (with scapy module) examples but couldn't find any difference to justify a drop by scapy

Scapy version

2.5.0

Python version

3.10.12

Operating system

Ubuntu 22.04.2 LTS

Additional environment information

No response

How to reproduce

scapy code which i use to request ndstats

ans, unans = sr(IP(dst=str(ip)) / UDP(sport=randint(1024, 65534), dport=137) / data, timeout=3, verbose=0)

socket basic send receive which works

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.settimeout(2)
        s.sendto(data, (addr, 137))
        rep = s.recv(2000)

Actual result

No response

Expected result

No response

Related resources

No response

[giovanni-bellini-argo]

activating sniff in a thread with the appropriate filters and then sending the packets i can see the answers which i should receive with sr or sr1.

[gpotter2]

What's data ? Could you provide a pcap? Scapy is not matching the answer to your request.

[giovanni-bellini-argo]

data contains the NetBios wildcard name padded with nulls, nothing special. it's just a string.

i can't provide pcap files as of now but i can attest that wireshark sees and recognizes the packets sent as well as the received one. just scapy dosen't seem to see it

[gpotter2]

Yeah, please either provide a pcap or a reproducible example.