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Port 6242 (jeol-nsdtp-2, jeol-nsddp-2)

IANA assigns port 6242 to jeol-nsdtp-2, jeol-nsddp-2: JEOL Network Services Data Transport Protocol 2.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
jeol-nsdtp-2 TCP JEOL Network Services Data Transport Protocol 2 Kevin Wellwood -
jeol-nsddp-2 UDP JEOL Network Services Dynamic Discovery Protocol 2 Kevin Wellwood -

Registry dates for this port: registered 2008-04-17.

Check what is listening on port 6242

Linux: is anything listening on TCP 6242?
sudo ss -tlnp 'sport = :6242'
Linux: UDP 6242
sudo ss -ulnp 'sport = :6242'
Linux / macOS: which process owns the port
sudo lsof -nP -i :6242
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':6242 '
Windows (Command Prompt)
netstat -ano | findstr :6242
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 6242 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 6242
From Windows
Test-NetConnection HOST -Port 6242
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 6242

Block port 6242 in the firewall

ufw
sudo ufw deny 6242/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 6242 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 6242 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 6242' -Direction Inbound -Protocol TCP -LocalPort 6242 -Action Block
ufw
sudo ufw deny 6242/udp
iptables
sudo iptables -A INPUT -p udp --dport 6242 -j DROP
nftables
sudo nft add rule inet filter input udp dport 6242 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 6242' -Direction Inbound -Protocol UDP -LocalPort 6242 -Action Block

Related ports

6222radmind6241jeol-nsdtp-1, jeol-nsddp-16243jeol-nsdtp-3, jeol-nsddp-36244jeol-nsdtp-4, jeol-nsddp-4

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