How to Set Up UDP Uptime Monitoring

What is a UDP Check?

A UDP check sends a UDP datagram from Xitoring's global probing nodes to your service and waits for a valid reply. UDP is connectionless, so the only way to confirm a service is up is to send a payload it understands and verify it answers — a generic "open port" check isn't possible the way it is with TCP.

Use UDP checks for:

DNS resolvers (port 53)
NTP time servers (123)
Syslog receivers (514)
Game servers (Quake, Minecraft Bedrock, custom protocols)
VoIP / SIP infrastructure (5060)
Any custom UDP service that returns a known reply to a known request

What Gets Monitored

Response received — service replies to the probe payload within the timeout
Response content — optional substring/byte match against the reply
Response time — round-trip from each probing node
Geographic availability — service reachable from each region

Prerequisites

A reachable host (public IP or hostname)
The UDP port the service listens on
Firewall rules allowing UDP from Xitoring's probing IP ranges to that port
A probe payload the service will respond to (e.g., a DNS query, NTP request, or your custom binary)
Knowledge of the expected response shape so you can validate it

How to Set Up a UDP Check

Step 1: Create the Check

Log in to your Xitoring Dashboard
Go to Uptime → Add Check
Select UDP as the check type

Step 2: Configure the Probe

Enter the hostname or IP (e.g., ns1.example.com)
Set the port (e.g., 53 for DNS)
Provide the payload to send — a hex or text payload the service understands
Set the expected response — substring or pattern to match in the reply
Set the check interval (30 seconds to 15 minutes)
Set the timeout (default: 30 seconds)

Step 3: Choose Probing Nodes

Select at least 3 probing nodes in regions where clients use the service. UDP delivery can be lossy — multi-node confirmation is essential to avoid false positives.

Step 4: Assign Notifications

Under Triggers, attach a notification role.

Step 5: Save and Verify

Save the check. The first probe runs immediately.

Setting Up Triggers

Common alerting rules:

No response — datagram sent but no reply within timeout
Response mismatch — reply received but doesn't match expected pattern
Slow response — round-trip exceeds threshold
Confirmed down — failures across multiple probing nodes

Tips

UDP is unreliable by design — single packets can be dropped without any error. Always require multi-node confirmation before alerting
For DNS uptime, prefer the dedicated DNS check — it handles record validation natively and is easier to configure than a raw UDP probe
A "port open" UDP check isn't a thing — without a meaningful payload and expected reply, you can't tell the service from a black hole. Put thought into the probe
Watch packet loss patterns — repeated UDP failures from a single region usually mean network conditions, not your service
Cloud security groups treat UDP separately from TCP — confirm explicit UDP allow rules from Xitoring's probing IPs