Port 126 (nxedit)

IANA assigns port 126 to nxedit: NXEdit.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference

nxedit TCP NXEdit
Port 126 Previously assigned to application below unitary 126/tcp Unisys Unitary Login unitary 126/udp Unisys Unitary Login <feil&kronos.nisd.cam.unisys.com> Port 126 Previously assigned to application above Don Payette -

nxedit UDP NXEdit
Port 126 Previously assigned to application below unitary 126/tcp Unisys Unitary Login unitary 126/udp Unisys Unitary Login <feil&kronos.nisd.cam.unisys.com> Port 126 Previously assigned to application above Don Payette -

Check what is listening on port 126

Linux: is anything listening on TCP 126?

sudo ss -tlnp 'sport = :126'

Linux: UDP 126

sudo ss -ulnp 'sport = :126'

Linux / macOS: which process owns the port

sudo lsof -nP -i :126

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':126 '

Windows (Command Prompt)

netstat -ano | findstr :126

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 126 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 126

From Windows

Test-NetConnection HOST -Port 126

UDP probe (no reply does not prove it is closed)

nc -vzu -w 5 HOST 126

Block port 126 in the firewall

ufw

sudo ufw deny 126/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 126 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 126 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 126' -Direction Inbound -Protocol TCP -LocalPort 126 -Action Block

ufw

sudo ufw deny 126/udp