DNS and naming ports
Overview
An open resolver can be abused for amplification attacks. Restrict recursive queries to trusted clients and keep zone transfer access closed.
Ports in this category10
Range coveredAll registry ranges
All DNS and naming port numbers
Every port below is assigned to this category in the registry or by a widely used convention. Open a port for its check and block commands, risk rating and troubleshooting notes.
| Port | Service | Transport | Risk | Description |
|---|---|---|---|---|
| 53 | DOMAIN | TCP / UDP | Medium | Domain Name Server |
| 90 | DNSIX | TCP / UDP | Standard/Low | DNSIX Securit Attribute Token Map |
| 195 | DN6-NLM-AUD | TCP / UDP | Standard/Low | DNSIX Network Level Module Audit |
| 196 | DN6-SMM-RED | TCP / UDP | Standard/Low | DNSIX Session Mgt Module Audit Redir |
| 558 | SDNSKMP | TCP / UDP | Standard/Low | SDNSKMP |
| 853 | DOMAIN-S | TCP / UDP | Standard/Low | DNS query-response protocol run over DTLS or QUIC |
| 5353 | MDNS | TCP / UDP | Standard/Low | Multicast DNS |
| 5354 | MDNSRESPONDER | TCP / UDP | Standard/Low | Multicast DNS Responder IPC |
| 8953 | UB-DNS-CONTROL | TCP | Standard/Low | unbound dns nameserver control |
| 9966 | ODNSP | TCP / UDP | Standard/Low | OKI Data Network Setting Protocol |
Other categories
Authentication and access 19Caching and in-memory stores 10Containers and orchestration 10Databases 54Development servers 13Directory services 14Email 26File transfer and sharing 27Gaming 6Infrastructure and administration 30IoT and device telemetry 7Message queues and streaming 17Monitoring and metrics 29Networking and proxies 31Printing 19RPC and service APIs 14Remote access 29Time synchronization 10VPN and tunnelling 10Voice and real-time media 29Web and HTTP 62Windows networking 14
Primary data: IANA Service Name and Transport Protocol Port Number Registry, plus clearly marked community conventions.
Last reviewed 2026-10-30 · Methodology · About · Privacy