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// File transfer & sharing

Port 497: Retrospect backup and restore service

Port 497 is assigned by IANA to retrospect (Retrospect backup and restore service).

497

How retrospect works

File transfer & sharing
client:4971/32/33/3retrospect client:4971/32/33/3retrospect

Files are sent over port 497 in pieces and reassembled on the other side.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Well-known (0-1023)
Category
File transfer & sharing
01 Security

Is port 497 dangerous?

We have no specific security note for port 497. Its risk depends on the program actually listening on it. General advice for file transfer & sharing services:

  • Prefer encrypted protocols (SFTP, FTPS, SMB 3 with encryption).
  • Disable anonymous access and restrict shares or exports to known hosts.
  • Never publish file sharing protocols to the Internet.
02 Registry

IANA registry entries for port 497

ServicePortTransportDescriptionReferenceUpdated
retrospect 497 TCP, UDP Retrospect backup and restore service - 2012-02-02

// source: IANA service name and port number registry

03 Check it

Which program uses port 497, and is it reachable?

Linux

sudo ss -ltnup 'sport = :497'      # process listening on 497
sudo lsof -nP -i :497

macOS

sudo lsof -nP -i :497

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 497 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 497
netstat -ano | findstr :497

From another machine

nmap -p 497 -sV <host>
sudo nmap -sU -p 497 <host>
nc -zv <host> 497

Block it in the firewall

sudo ufw deny 497/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 497" -Direction Inbound -LocalPort 497 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 497 used for?

Port 497 is assigned by IANA to retrospect (Retrospect backup and restore service).

Is port 497 TCP or UDP?

Port 497 is registered for TCP and UDP.

Is it safe to open port 497?

It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Prefer encrypted protocols (SFTP, FTPS, SMB 3 with encryption).

How do I check if port 497 is open?

On Linux run "ss -ltnup 'sport = :497'", on macOS "lsof -nP -i :497", and on Windows "netstat -ano | findstr :497" to see the local process. From another machine, "nmap -p 497 <host>" shows whether it is reachable.

05 Related
:445 SMB tcp · udp · critical risk :21 FTP tcp · udp · sctp · high risk :139 NetBIOS Session tcp · udp · high risk :69 TFTP udp · tcp · high risk :2049 NFS tcp · udp · sctp · high risk :873 rsync tcp · udp · high risk :20 File Transfer [Default Data] tcp · udp · sctp :115 Simple File Transfer Protocol tcp · udp

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