HTTPfy

Port 202 (at-nbp)

IANA assigns port 202 to at-nbp: AppleTalk Name Binding.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
at-nbp TCP AppleTalk Name Binding - -
at-nbp UDP AppleTalk Name Binding - -

Check what is listening on port 202

Linux: is anything listening on TCP 202?
sudo ss -tlnp 'sport = :202'
Linux: UDP 202
sudo ss -ulnp 'sport = :202'
Linux / macOS: which process owns the port
sudo lsof -nP -i :202
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':202 '
Windows (Command Prompt)
netstat -ano | findstr :202
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 202 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 202
From Windows
Test-NetConnection HOST -Port 202
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 202

Block port 202 in the firewall

ufw
sudo ufw deny 202/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 202 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 202 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 202' -Direction Inbound -Protocol TCP -LocalPort 202 -Action Block
ufw
sudo ufw deny 202/udp
iptables
sudo iptables -A INPUT -p udp --dport 202 -j DROP
nftables
sudo nft add rule inet filter input udp dport 202 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 202' -Direction Inbound -Protocol UDP -LocalPort 202 -Action Block

Related ports

200src201at-rtmp203at-3204at-echo

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