HTTPfy

Port 6101 (synchronet-rtc)

IANA assigns port 6101 to synchronet-rtc: SynchroNet-rtc.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
synchronet-rtc TCP SynchroNet-rtc Arne Haugland -
synchronet-rtc UDP SynchroNet-rtc Arne Haugland -

Check what is listening on port 6101

Linux: is anything listening on TCP 6101?
sudo ss -tlnp 'sport = :6101'
Linux: UDP 6101
sudo ss -ulnp 'sport = :6101'
Linux / macOS: which process owns the port
sudo lsof -nP -i :6101
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':6101 '
Windows (Command Prompt)
netstat -ano | findstr :6101
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 6101 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 6101
From Windows
Test-NetConnection HOST -Port 6101
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 6101

Block port 6101 in the firewall

ufw
sudo ufw deny 6101/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 6101 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 6101 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 6101' -Direction Inbound -Protocol TCP -LocalPort 6101 -Action Block
ufw
sudo ufw deny 6101/udp
iptables
sudo iptables -A INPUT -p udp --dport 6101 -j DROP
nftables
sudo nft add rule inet filter input udp dport 6101 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 6101' -Direction Inbound -Protocol UDP -LocalPort 6101 -Action Block

Related ports

6099raxa-mgmt6100synchronet-db6102synchronet-upd6103rets

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