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Port 4101 (brlp-0)

IANA assigns port 4101 to brlp-0: Braille protocol.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
brlp-0 TCP Braille protocol - -
brlp-0 UDP Braille protocol - -

Check what is listening on port 4101

Linux: is anything listening on TCP 4101?
sudo ss -tlnp 'sport = :4101'
Linux: UDP 4101
sudo ss -ulnp 'sport = :4101'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4101
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4101 '
Windows (Command Prompt)
netstat -ano | findstr :4101
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4101 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4101
From Windows
Test-NetConnection HOST -Port 4101
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4101

Block port 4101 in the firewall

ufw
sudo ufw deny 4101/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4101 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4101 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4101' -Direction Inbound -Protocol TCP -LocalPort 4101 -Action Block
ufw
sudo ufw deny 4101/udp
iptables
sudo iptables -A INPUT -p udp --dport 4101 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4101 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4101' -Direction Inbound -Protocol UDP -LocalPort 4101 -Action Block

Related ports

4099dpcp4100igo-incognito4102brlp-14103brlp-2

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