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Port 2065 (dlsrpn)

IANA assigns port 2065 to dlsrpn: Data Link Switch Read Port Number.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
dlsrpn TCP Data Link Switch Read Port Number Amir Peless -
dlsrpn UDP Data Link Switch Read Port Number Amir Peless -

Check what is listening on port 2065

Linux: is anything listening on TCP 2065?
sudo ss -tlnp 'sport = :2065'
Linux: UDP 2065
sudo ss -ulnp 'sport = :2065'
Linux / macOS: which process owns the port
sudo lsof -nP -i :2065
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':2065 '
Windows (Command Prompt)
netstat -ano | findstr :2065
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 2065 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 2065
From Windows
Test-NetConnection HOST -Port 2065
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 2065

Block port 2065 in the firewall

ufw
sudo ufw deny 2065/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 2065 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 2065 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 2065' -Direction Inbound -Protocol TCP -LocalPort 2065 -Action Block
ufw
sudo ufw deny 2065/udp
iptables
sudo iptables -A INPUT -p udp --dport 2065 -j DROP
nftables
sudo nft add rule inet filter input udp dport 2065 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 2065' -Direction Inbound -Protocol UDP -LocalPort 2065 -Action Block

Related ports

2063icg-bridge2064icg-iprelay2066aura2067dlswpn

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