- Patch VPN gateways quickly: they are a top initial access target.
- Use certificates or MFA rather than shared secrets.
- Investigate unexpected tunnels and proxies: they are also attacker tools.
Port 363: RSVP Tunnel
Port 363 is assigned by IANA to rsvp_tunnel (RSVP Tunnel), rsvp-tunnel (RSVP Tunnel IANA assigned this well-formed service name as a replacement for "rsvp_tunnel".).
363
How rsvp_tunnel works
VPN, tunnels & proxiesTraffic is wrapped in a tunnel between the two ends, so the network in between only sees the tunnel.
- Transport
- TCP · UDP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned2 registered services
- Range
- Well-known (0-1023)
- Category
- VPN, tunnels & proxies
Is port 363 dangerous?
We have no specific security note for port 363. Its risk depends on the program actually listening on it. General advice for vpn, tunnels & proxies services:
IANA registry entries for port 363
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| rsvp_tunnel | 363 | TCP, UDP | RSVP Tunnel | - | - |
| rsvp-tunnel | 363 | TCP, UDP | RSVP Tunnel IANA assigned this well-formed service name as a replacement for "rsvp_tunnel". | - | - |
// source: IANA service name and port number registry
Which program uses port 363, and is it reachable?
Linux
sudo ss -ltnup 'sport = :363' # process listening on 363
sudo lsof -nP -i :363macOS
sudo lsof -nP -i :363
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 363 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 363 netstat -ano | findstr :363
From another machine
nmap -p 363 -sV <host> sudo nmap -sU -p 363 <host> nc -zv <host> 363
Block it in the firewall
sudo ufw deny 363/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 363" -Direction Inbound -LocalPort 363 -Protocol TCP -Action Block # Windows
What is port 363 used for?
Port 363 is assigned by IANA to rsvp_tunnel (RSVP Tunnel), rsvp-tunnel (RSVP Tunnel IANA assigned this well-formed service name as a replacement for "rsvp_tunnel".).
Is port 363 TCP or UDP?
Port 363 is registered for TCP and UDP.
Is it safe to open port 363?
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. Patch VPN gateways quickly: they are a top initial access target.
How do I check if port 363 is open?
On Linux run "ss -ltnup 'sport = :363'", on macOS "lsof -nP -i :363", and on Windows "netstat -ano | findstr :363" to see the local process. From another machine, "nmap -p 363 <host>" shows whether it is reachable.