R3204P16-HP Load Balancing Module High Availability Configuration Guide-6PW101

52
NOTE:
NQA DNS tests do not support the action of sending trap messages. The action to be triggered in DNS
tests can only be the default one, none.
4. Reaction entry
In a reaction entry, a monitored element, a threshold type, and the action to be triggered are configured
to implement threshold monitoring.
The state of a reaction entry can be invalid, over-threshold, or below-threshold. Before an NQA test
group starts, the reaction entry is in the state of invalid. After each test or probe, threshold violations are
counted according to the threshold type and range configured in the entry. If the threshold is violated
consecutively or accumulatively for a specified number of times, the state of the entry is set to
over-threshold; otherwise, the state of the entry is set to below-threshold.
If the action to be triggered is configured as trap-only for a reaction entry, when the state of the entry
changes, a trap message is generated and sent to the network management server.
Basic NQA concepts
Test group
An NQA test group specifies test parameters including the test type, destination address, and destination
port. Each test group is uniquely identified by an administrator name and operation tag. You can
configure and schedule multiple NQA test groups to test different objects.
Test and probe
After the NQA test group starts, tests are performed at a specified interval. During each test, a specified
number of probe operations are performed. Both the test interval and the number of probe operations
per test are configurable.
Probe operations vary with NQA test types.
• During a TCP or DLSw test, one probe operation means setting up one connection.
• During a UDP jitter test, one probe operation means continuously sending a specified number of
probe packets. The number of probe packets is configurable.
• During an FTP, HTTP, DHCP or DNS test, one probe operation means uploading or downloading a
file, obtaining a web page, obtaining an IP address through DHCP, or translating a domain name
to an IP address.
• During an ICMP echo or UDP echo test, one probe operation means sending an ICMP echo request
or a UDP packet.
• During an SNMP test, one probe operation means sending one SNMPv1 packet, one SNMPv2C
packet, and one SNMPv3 packet.
NQA client and server
A device with NQA test groups configured is an NQA client and the NQA client initiates NQA tests. An
NQA server makes responses to probe packets destined to the specified destination address and port
number.