HTTPfy

Port 4454 (nssagentmgr)

IANA assigns port 4454 to nssagentmgr: NSS Agent Manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
nssagentmgr TCP NSS Agent Manager Jim Hill -
nssagentmgr UDP NSS Agent Manager Jim Hill -

Check what is listening on port 4454

Linux: is anything listening on TCP 4454?
sudo ss -tlnp 'sport = :4454'
Linux: UDP 4454
sudo ss -ulnp 'sport = :4454'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4454
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4454 '
Windows (Command Prompt)
netstat -ano | findstr :4454
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4454 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4454
From Windows
Test-NetConnection HOST -Port 4454
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4454

Block port 4454 in the firewall

ufw
sudo ufw deny 4454/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4454 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4454 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4454' -Direction Inbound -Protocol TCP -LocalPort 4454 -Action Block
ufw
sudo ufw deny 4454/udp
iptables
sudo iptables -A INPUT -p udp --dport 4454 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4454 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4454' -Direction Inbound -Protocol UDP -LocalPort 4454 -Action Block

Related ports

4452ctiprogramload4453nssalertmgr4455prchat-user4456prchat-server

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