Port Monitoring

Verify the ports that matter are open.
Or that they stay closed.

Establish real TCP/UDP connections to any host or IP. Confirm SMTP, VPN, Redis, and core services are listening, and surface routing issues before production is impacted.

cache.internal:6379

TCP cache.internal:6379

OPEN
8ms
Response Time
ProtocolTCP
Connect Time 8ms
Port 6379 reachableOPEN

Real connections. Not just pings.

A port scanner tells you a port is open. NoDisrupt establishes a full TCP connection, measures how long it takes, and alerts you the moment that changes, whether a service stops listening or a firewall rule silently blocks traffic.

All Ports Up
Reachability Check
TCP
smtp.internal:25
6msOPEN
UDP
vpn.internal:1194
11msOPEN
TCP
cache.internal:6379
8msOPEN
Check interval: 60sLast checked: just now

TCP/UDP reachability

Go beyond ICMP ping. NoDisrupt establishes real TCP connections and validates UDP reachability against any host or IP, so you know SMTP is accepting mail, VPN is listening, and Redis is serving connections.

  • Confirm essential services are listening
  • Detect closed or blocked ports before impact
  • Check from your chosen regions

Connection-time latency

Measure the exact time it takes to establish each TCP connection. A port can be technically open and still be dangerously slow, catch connection-time degradation before it cascades into timeouts and dropped requests.

  • Track TCP connect latency
  • Alert when connection time degrades
  • Trend performance over time

Connect Time, cache.internal:6379

DNS Resolution2ms
TCP SYN / SYN-ACK4ms
Total Connect Time8ms
Threshold: 25ms
StatusWithin threshold

Multi-Port Scan, db.internal

22SSH
5msOPEN
443HTTPS
9msOPEN
6379Redis
8msOPEN
3306MySQL
--CLOSED
3 open, 1 closed, last scan 45s ago

Routing & multi-port

Network paths change. Firewall rules drift. Watch multiple ports per host in a single monitor and get alerted when a port that should be open disappears, or one that should be closed quietly opens up.

  • Surface routing issues between monitor and host
  • Watch multiple ports per host
  • Catch firewall/ACL changes

Know before the connection refuses.

Start monitoring your ports in under a minute.

Create Your First Monitor