[ ~]$ nc -v -u -z -w 3 targethost 25826 Ncat: Version 7.50 ( https://nmap.org/ncat ) Ncat: Connected to 192.168.1.2:25826. Ncat: UDP packet sent successfully Ncat: 1 bytes sent, 0 bytes received in 2.03 seconds. [ ~]$ nc -v -u -z -w 3 targethost 25828 Ncat: Version 7.50 ( https://nmap.org/ncat ) Ncat: Connected to 192.168.1.2:25828. Ncat: Connection refused.
WAN monitoring - Ethernet OAM - Y.1731
Essentially a formalised version of Cisco SAA probes You really want to use the two way delay probes but this requires hardware at both ends with accurate clocks and support for it.
Generate an Alarm (aka re-raise it)
./test-alert.php -r 8 -d -h host
Validate Transport logic but doesnt send anything
./test-template.php -t 0 -h host -r 8 -d