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Port 411 (rmt)

IANA assigns port 411 to rmt: Remote MT Protocol.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
rmt TCP Remote MT Protocol Peter Eriksson -
rmt UDP Remote MT Protocol Peter Eriksson -

Check what is listening on port 411

Linux: is anything listening on TCP 411?
sudo ss -tlnp 'sport = :411'
Linux: UDP 411
sudo ss -ulnp 'sport = :411'
Linux / macOS: which process owns the port
sudo lsof -nP -i :411
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':411 '
Windows (Command Prompt)
netstat -ano | findstr :411
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 411 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 411
From Windows
Test-NetConnection HOST -Port 411
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 411

Block port 411 in the firewall

ufw
sudo ufw deny 411/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 411 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 411 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 411' -Direction Inbound -Protocol TCP -LocalPort 411 -Action Block
ufw
sudo ufw deny 411/udp
iptables
sudo iptables -A INPUT -p udp --dport 411 -j DROP
nftables
sudo nft add rule inet filter input udp dport 411 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 411' -Direction Inbound -Protocol UDP -LocalPort 411 -Action Block

Related ports

409prm-nm410decladebug412synoptics-trap413smsp

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