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Port 2741 (tsb)

IANA assigns port 2741 to tsb: TSB.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
tsb TCP TSB - -
tsb UDP TSB - -

Check what is listening on port 2741

Linux: is anything listening on TCP 2741?
sudo ss -tlnp 'sport = :2741'
Linux: UDP 2741
sudo ss -ulnp 'sport = :2741'
Linux / macOS: which process owns the port
sudo lsof -nP -i :2741
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':2741 '
Windows (Command Prompt)
netstat -ano | findstr :2741
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 2741 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 2741
From Windows
Test-NetConnection HOST -Port 2741
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 2741

Block port 2741 in the firewall

ufw
sudo ufw deny 2741/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 2741 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 2741 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 2741' -Direction Inbound -Protocol TCP -LocalPort 2741 -Action Block
ufw
sudo ufw deny 2741/udp
iptables
sudo iptables -A INPUT -p udp --dport 2741 -j DROP
nftables
sudo nft add rule inet filter input udp dport 2741 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 2741' -Direction Inbound -Protocol UDP -LocalPort 2741 -Action Block

Related ports

2739tn-timing2740alarm2742tsb22743murx

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