Port 90 is an IANA System Port assigned to dnsix (DNSIX Securit Attribute Token Map) over TCP and UDP.
- Port: 90
- Service dnsix: TCP, UDP — DNSIX Securit Attribute Token Map
- Unauthorized use reported (TCP, UDP): PORT 90 also being used unofficially by Pointcast
- Range: System Ports (0–1023)