Port 1494 (Citrix ICA)

Citrix Virtual Apps and Desktops ICA protocol; 2598 carries session reliability (CGP).

Registered (user) port, 1024-49151 TCP Remote access Do not expose to the internet

What port 1494 is used for

Citrix Virtual Apps and Desktops ICA protocol; 2598 carries session reliability (CGP).

Security: should port 1494 be open?

Do not expose to the internet. Publish Citrix through a Gateway (NetScaler) on 443 rather than exposing 1494; keep the gateway patched (CitrixBleed, CVE-2023-4966).

IANA assignment

Service nameProtoDescriptionAssigneeReference

ica TCP ica John Richardson -

ica UDP ica John Richardson -

Check what is listening on port 1494

Linux: is anything listening on TCP 1494?

sudo ss -tlnp 'sport = :1494'

Linux / macOS: which process owns the port

sudo lsof -nP -i :1494

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':1494 '

Windows (Command Prompt)

netstat -ano | findstr :1494

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 1494 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 1494

From Windows

Test-NetConnection HOST -Port 1494

Block port 1494 in the firewall

ufw

sudo ufw deny 1494/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 1494 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 1494 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 1494' -Direction Inbound -Protocol TCP -LocalPort 1494 -Action Block

All port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.