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Bug #6400

open

log of DNS answer is in wrong direction

Added by Eric Leblond about 1 year ago. Updated 9 months ago.

Status:
New
Priority:
Normal
Assignee:
Target version:
Affected Versions:
Effort:
Difficulty:
Label:

Description

I think we did already discuss this issue but I can still not understand this. In DNS request and answer the source and destination IP are the same. This does not appear to be logic as we are facing communication in opposite direction.

For example, on a pcap replay we have:

{
  "timestamp": "2019-07-05T22:10:33.164698+0200",
  "flow_id": 425900207853173,
  "pcap_cnt": 48630,
  "event_type": "dns",
  "src_ip": "10.7.5.101",
  "src_port": 50643,
  "dest_ip": "10.7.5.5",
  "dest_port": 53,
  "proto": "UDP",
  "pkt_src": "wire/pcap",
  "ether": {
    "src_mac": "00:08:02:1c:47:ae",
    "dest_mac": "a4:1f:72:c2:09:6a" 
  },
  "community_id": "1:kTeBZP87R9S9OU6Vd9RX0LnViA8=",
  "dns": {
    "type": "query",
    "id": 62832,
    "rrname": "germakhya.xyz",
    "rrtype": "A",
    "tx_id": 0,
    "opcode": 0
  }
}
{
  "timestamp": "2019-07-05T22:10:33.369515+0200",
  "flow_id": 425900207853173,
  "pcap_cnt": 48631,
  "event_type": "dns",
  "src_ip": "10.7.5.101",
  "src_port": 50643,
  "dest_ip": "10.7.5.5",
  "dest_port": 53,
  "proto": "UDP",
  "pkt_src": "wire/pcap",
  "ether": {
    "src_mac": "a4:1f:72:c2:09:6a",
    "dest_mac": "00:08:02:1c:47:ae" 
  },
  "community_id": "1:kTeBZP87R9S9OU6Vd9RX0LnViA8=",
  "dns": {
    "version": 2,
    "type": "answer",
    "id": 62832,
    "flags": "8180",
    "qr": true,
    "rd": true,
    "ra": true,
    "opcode": 0,
    "rrname": "germakhya.xyz",
    "rrtype": "A",
    "rcode": "NOERROR",
    "answers": [
      {
        "rrname": "germakhya.xyz",
        "rrtype": "A",
        "ttl": 599,
        "rdata": "95.142.46.236" 
      }
    ],
    "grouped": {
      "A": [
        "95.142.46.236" 
      ]
    }
  }
}

And if you look at the ethernet address you can see that they are reverted between the request and the answer. This is not making sense at all.


Related issues 3 (1 open2 closed)

Related to Suricata - Bug #6281: dns: structure of query differs between "alert" and "dns" event typesClosedJason IshActions
Related to Suricata - Optimization #3827: clean up logging initialization codeClosedPhilippe AntoineActions
Related to Suricata - Task #2167: tracking: eve enhancementsNewOISF DevActions
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