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Port 677 (vpp)

IANA assigns port 677 to vpp: Virtual Presence Protocol.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
vpp TCP Virtual Presence Protocol Klaus Wolf -
vpp UDP Virtual Presence Protocol Klaus Wolf -

Check what is listening on port 677

Linux: is anything listening on TCP 677?
sudo ss -tlnp 'sport = :677'
Linux: UDP 677
sudo ss -ulnp 'sport = :677'
Linux / macOS: which process owns the port
sudo lsof -nP -i :677
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':677 '
Windows (Command Prompt)
netstat -ano | findstr :677
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 677 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 677
From Windows
Test-NetConnection HOST -Port 677
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 677

Block port 677 in the firewall

ufw
sudo ufw deny 677/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 677 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 677 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 677' -Direction Inbound -Protocol TCP -LocalPort 677 -Action Block
ufw
sudo ufw deny 677/udp
iptables
sudo iptables -A INPUT -p udp --dport 677 -j DROP
nftables
sudo nft add rule inet filter input udp dport 677 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 677' -Direction Inbound -Protocol UDP -LocalPort 677 -Action Block

Related ports

675dctp676vpps-via678ggf-ncp679mrm

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