HTTPfy

Port 3302 (mcs-fastmail)

IANA assigns port 3302 to mcs-fastmail: MCS Fastmail.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
mcs-fastmail TCP MCS Fastmail Patti Jo Newsom -
mcs-fastmail UDP MCS Fastmail Patti Jo Newsom -

Check what is listening on port 3302

Linux: is anything listening on TCP 3302?
sudo ss -tlnp 'sport = :3302'
Linux: UDP 3302
sudo ss -ulnp 'sport = :3302'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3302
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3302 '
Windows (Command Prompt)
netstat -ano | findstr :3302
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3302 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3302
From Windows
Test-NetConnection HOST -Port 3302
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3302

Block port 3302 in the firewall

ufw
sudo ufw deny 3302/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3302 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3302 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3302' -Direction Inbound -Protocol TCP -LocalPort 3302 -Action Block
ufw
sudo ufw deny 3302/udp
iptables
sudo iptables -A INPUT -p udp --dport 3302 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3302 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3302' -Direction Inbound -Protocol UDP -LocalPort 3302 -Action Block

Related ports

3300ceph3301tarantool3303opsession-clnt3304opsession-srvr

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