01
Choose the registry family
Port 6 and IP protocol number 6 are different fields. Set the family before searching, and use the DNS example to see MX as type 15.
Developer reference
network protocol referencewith original sources
Pick a registry family, then search a number or name. Results are a checked local selection, with links to the full source.
network protocol reference
Matches
443 · https
TCPRegistry family: Ports
Reference note (English): http protocol over TLS/SSL
Original sourceSearches use local data; only opening a source link visits another site.
Registry family
Transport
Showing 2 of 2 matches; 30 selected entries in this family
Selection checked 2026-09-23Open full registry
A firewall rule showing 443, a packet capture showing protocol 6, and a DNS answer showing type 15 use different number spaces. This network protocol reference keeps them separate before you interpret a value.
Use this network protocol reference as a fast port number lookup when reading logs or configuration. The selected entries carry an English reference note and a link for checking current assignments.
Why use this network protocol reference
One search panel, with each number tied to the right registry.
Separate number spaces
A value such as 53 means a DNS service port in one registry and SMIMEA in DNS record types. The category choice prevents an accidental cross-registry answer.
Keep transport assignments distinct
IANA lists 443/TCP and 443/UDP separately. The result cards preserve both rows and their source instead of claiming that either service is active on a host.
Read the right number space first
02
Narrow transport when it matters
For ports, All can show more than one transport registration. Select TCP or UDP and submit again; the previous copy action stays disabled until results refresh.
03
Check the source and snapshot date
Open the original registry for current or omitted assignments. This page shows a curated snapshot checked on 23 September 2026, not a live scan.
Fast lookup across distinct registries
Numbers and names
Search a number, mnemonic or service name; port number lookup works alongside DNS record types and IP protocol numbers.
Seven focused families
Ports, DNS, IP protocols, ICMPv4, ICMPv6, TLS parameters and all 17 gRPC status codes are separated so identical numbers keep their proper meaning.
Provenance on every result
Each selected item has an English reference note, a direct official source, and the date this local network protocol reference was checked.
What a registry result can and cannot tell you
- Registration is not observation
- An IANA port assignment is not proof that a process listens there. This page sends no probe and cannot say whether a host has the port open.
- The index is deliberately selected
- No match means this local selection omits the item; it does not mean IANA left the number unassigned. Follow the full registry link for the current list.
- Versions and codes stay separate
- ICMPv4 and ICMPv6 have different type spaces. TLS 1.3 cipher suite identifiers do not automatically apply to TLS 1.2; an IANA Recommended N is not a security verdict.
- No gateway status conversion
- A gRPC status describes an RPC result. The tool does not invent a unique HTTP equivalent or tell you to retry non-idempotent calls.
Network protocol reference questions
What service is assigned to port 443?
IANA lists https on both TCP and UDP port 443. The entries are registrations; they do not show whether a particular host is running HTTPS or QUIC.
Can TCP and UDP use the same port number?
Yes. TCP and UDP are distinct transport namespaces. The port number lookup displays the selected registrations as separate rows, such as 53/TCP and 53/UDP.
Does a registered port prove that a service is running?
No. A registration says what use is assigned, not what an observed host is doing. A live check needs a separate diagnostic tool and an authorized target.
What is the difference between A and AAAA DNS records?
A is DNS RR type 1 for an IPv4 host address; AAAA is type 28 for an IPv6 address. Both appear under DNS record types, not under ports.
Which gRPC status code means a service is unavailable?
UNAVAILABLE is code 14. It signals a transient service condition in many cases, but the correct retry action depends on the RPC and whether repeating it is safe.
Missing an entry or source?
Use the network protocol reference now
Choose the number space, inspect the selected assignment and open its original registry when accuracy matters.