HTTPfy

Port 4800 (iims)

IANA assigns port 4800 to iims: Icona Instant Messenging System.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
iims TCP Icona Instant Messenging System - -
iims UDP Icona Instant Messenging System - -

Check what is listening on port 4800

Linux: is anything listening on TCP 4800?
sudo ss -tlnp 'sport = :4800'
Linux: UDP 4800
sudo ss -ulnp 'sport = :4800'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4800
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4800 '
Windows (Command Prompt)
netstat -ano | findstr :4800
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4800 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4800
From Windows
Test-NetConnection HOST -Port 4800
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4800

Block port 4800 in the firewall

ufw
sudo ufw deny 4800/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4800 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4800 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4800' -Direction Inbound -Protocol TCP -LocalPort 4800 -Action Block
ufw
sudo ufw deny 4800/udp
iptables
sudo iptables -A INPUT -p udp --dport 4800 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4800 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4800' -Direction Inbound -Protocol UDP -LocalPort 4800 -Action Block

Related ports

4793uet4794veroce4801iwec4802ilss

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