# WHATPORT(497)

## NAME

port 497 — Retrospect backup — A Retrospect backup client waiting for its backup server to call — still shipping software, common on Macs.

Protocol: TCP/UDP  
IANA: retrospect

## DESCRIPTION

Retrospect is a long-running backup product for macOS, Windows and Linux, and 497 is its IANA-assigned port on both TCP and UDP. The client agent on each protected machine listens here, and the backup server uses the same port — including subnet broadcast and multicast — to discover and reach clients, which is why Retrospect's own firewall guidance says to open 497 TCP and UDP on both ends. On a Mac network it is one of the more common unexpected open ports, because installing the client opens it automatically.

## EXPOSURE

**Do not expose.** A backup agent reads every file on the machine — anything that can authenticate to it can pull the whole filesystem, so keep it strictly on the backup network.

## CHECK

```sh
nc -vz -w 3 TARGET 497
```

## SEE ALSO

- docs — [Retrospect — Opening your network firewall for Retrospect](https://docs.retrospect.com/docs/opening-your-network-firewall-for-retrospect) (docs.retrospect.com)
- iana — [IANA Service Name and Transport Protocol Port Number Registry — 497](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=497) (iana.org)

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HTML: <https://whatport.net/497/> · JSON: <https://whatport.net/497.json> · full dataset: <https://whatport.net/ports.json>