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Port 351 (matip-type-b, bhoetty)

IANA assigns port 351 to matip-type-b, bhoetty: MATIP Type B.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
matip-type-b TCP MATIP Type B Alain Robert RFC 2351
bhoetty TCP bhoetty
This entry records an unassigned but widespread use (added 5/21/97) John Kelly -
matip-type-b UDP MATIP Type B Alain Robert RFC 2351
bhoetty UDP bhoetty
This entry records an unassigned but widespread use (added 5/21/97) John Kelly -

Check what is listening on port 351

Linux: is anything listening on TCP 351?
sudo ss -tlnp 'sport = :351'
Linux: UDP 351
sudo ss -ulnp 'sport = :351'
Linux / macOS: which process owns the port
sudo lsof -nP -i :351
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':351 '
Windows (Command Prompt)
netstat -ano | findstr :351
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 351 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 351
From Windows
Test-NetConnection HOST -Port 351
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 351

Block port 351 in the firewall

ufw
sudo ufw deny 351/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 351 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 351 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 351' -Direction Inbound -Protocol TCP -LocalPort 351 -Action Block
ufw
sudo ufw deny 351/udp
iptables
sudo iptables -A INPUT -p udp --dport 351 -j DROP
nftables
sudo nft add rule inet filter input udp dport 351 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 351' -Direction Inbound -Protocol UDP -LocalPort 351 -Action Block

Related ports

349mftp350matip-type-a352dtag-ste-sb, bhoedap4353ndsauth

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