Port 2855 (msrp)

IANA assigns port 2855 to msrp: MSRP over TCP.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference

msrp TCP MSRP over TCP - RFC 4976

Registry dates for this port: last modified 2014-04-09.

Linux: is anything listening on TCP 2855?

sudo ss -tlnp 'sport = :2855'

Linux / macOS: which process owns the port

sudo lsof -nP -i :2855

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':2855 '

Windows (Command Prompt)

netstat -ano | findstr :2855

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 2855 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 2855

From Windows

Test-NetConnection HOST -Port 2855

ufw

sudo ufw deny 2855/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 2855 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 2855 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 2855' -Direction Inbound -Protocol TCP -LocalPort 2855 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.