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Port 4557 (mtcevrunqss)

IANA assigns port 4557 to mtcevrunqss: Marathon everRun Quorum Service Server.

Registered (user) port, 1024-49151 UDP

Port 4557 is normally used over UDP; the checker tests TCP only, so a "filtered" result does not mean the UDP service is down.

IANA assignment

Service nameProtoDescriptionAssigneeReference
mtcevrunqss UDP Marathon everRun Quorum Service Server David Schwartz 2 -

Registry dates for this port: registered 2009-06-18.

Check what is listening on port 4557

Linux: UDP 4557
sudo ss -ulnp 'sport = :4557'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4557
Windows (Command Prompt)
netstat -ano | findstr :4557
Windows (PowerShell)
Get-NetUDPEndpoint -LocalPort 4557

Test it from outside

UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4557

Block port 4557 in the firewall

ufw
sudo ufw deny 4557/udp
iptables
sudo iptables -A INPUT -p udp --dport 4557 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4557 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4557' -Direction Inbound -Protocol UDP -LocalPort 4557 -Action Block

Related ports

4555rsip4556dtn-bundle4558mtcevrunqman4559hylafax

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