UDP traffic
Datagrams matching port:21711 sent to HoneyLabs sensors over UDP in the last 7 days. DNS questions and QUIC client fingerprints are decoded on the sensor. Other datagrams are kept as their first bytes and labelled by protocol where it can be recognised.
A UDP source address can be forged, so each address listed here either sent the traffic or was impersonated by whoever did. UDP traffic is kept out of verdicts, feeds, watchlists and alerts.
2
Datagrams
2
Source addresses
2
Networks
2
Countries
1
Destination ports
Traffic by type
Service queries
1 datagrams from 1 sourceRequests a service answers without a handshake. Scanners send them to find open DNS, NTP, SNMP or SSDP servers, which are also the servers reflection attacks abuse.
Latest NetBIOS datagram, to 21711/udp
payload bytes
00000000 e5 d8 00 00 00 01 00 00 00 00 00 00 20 43 4b 41 |............ CKA| 00000010 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 |AAAAAAAAAAAAAAAA| 00000020 41 41 41 41 41 41 41 41 41 41 41 41 41 00 00 21 |AAAAAAAAAAAAA..!| 00000030 00 01 |..|
Unrecognised
1 datagrams from 1 sourceDatagrams no decoder recognised. Their first bytes are kept.
Latest Unrecognised datagram, to 21711/udp
payload bytes
00000000 13 55 3b 11 bb b7 4f f3 4e 8a 17 2c c2 10 21 5e |.U;...O.N..,..!^| 00000010 d8 45 79 95 a3 ca |.Ey...|
Amplification checks
Probes for services that answer a small request with a much larger reply, the property reflection attacks rely on.
| Service | Port | Datagrams | Sources | Factor |
|---|---|---|---|---|
| NetBIOS | 21711/udp | 1 | 1 | 3.8 |
The factor is how many bytes a reachable server can send back for each byte it receives, as published by CISA in alert TA14-017A.
Destination ports
- 21711/udp NetBIOS2
Networks
- AS398324 Censys, Inc. from 1 source1
- AS7303 Telecom Argentina S.A. from 1 source1
Countries
Source addresses (unverified)
| Address | Network | Cc | Sends | Datagrams | Last seen (UTC) |
|---|---|---|---|---|---|
| 181.166.178.17 | AS7303 Telecom Argentina S.A. | AR | Unrecognised | 1 | 2026-10-07 07:21 |
| 66.132.172.242 | AS398324 Censys, Inc. | US | NetBIOS | 1 | 2026-10-10 15:34 |
Latest datagrams
payload bytes
00000000 e5 d8 00 00 00 01 00 00 00 00 00 00 20 43 4b 41 |............ CKA| 00000010 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 |AAAAAAAAAAAAAAAA| 00000020 41 41 41 41 41 41 41 41 41 41 41 41 41 00 00 21 |AAAAAAAAAAAAA..!| 00000030 00 01 |..|
payload bytes
00000000 13 55 3b 11 bb b7 4f f3 4e 8a 17 2c c2 10 21 5e |.U;...O.N..,..!^| 00000010 d8 45 79 95 a3 ca |.Ey...|