- 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 22305: CompactIS Tunnel
Port 22305 is assigned by IANA to cis (CompactIS Tunnel).
22305
How cis 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
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- VPN, tunnels & proxies
Is port 22305 dangerous?
We have no specific security note for port 22305. Its risk depends on the program actually listening on it. General advice for vpn, tunnels & proxies services:
IANA registry entries for port 22305
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| cis | 22305 | TCP, UDP | CompactIS Tunnel | - | 2007-08-16 |
// source: IANA service name and port number registry
Which program uses port 22305, and is it reachable?
Linux
sudo ss -ltnup 'sport = :22305' # process listening on 22305
sudo lsof -nP -i :22305macOS
sudo lsof -nP -i :22305
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 22305 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 22305 netstat -ano | findstr :22305
From another machine
nmap -p 22305 -sV <host> sudo nmap -sU -p 22305 <host> nc -zv <host> 22305
Block it in the firewall
sudo ufw deny 22305/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 22305" -Direction Inbound -LocalPort 22305 -Protocol TCP -Action Block # Windows
What is port 22305 used for?
Port 22305 is assigned by IANA to cis (CompactIS Tunnel).
Is port 22305 TCP or UDP?
Port 22305 is registered for TCP and UDP.
Is it safe to open port 22305?
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 22305 is open?
On Linux run "ss -ltnup 'sport = :22305'", on macOS "lsof -nP -i :22305", and on Windows "netstat -ano | findstr :22305" to see the local process. From another machine, "nmap -p 22305 <host>" shows whether it is reachable.