Exinda EXNV-10063, Руководство администратора

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Exinda Network Orchestrator 3 Using | 215
To understand how to set the desired time range for a chart, see
Setting the Time Range
.
To understand how to print the report or schedule the report, see Printing and Scheduling Reports .
Monitoring TCP health
The TCP Health report shows the number of aborted, refused, and ignored connections over time. The report can be
categorized by applications, internal hosts, or external hosts. You can drill into particular apps or hosts to view the health
for particular traffic.
This report can answers questions such as:
Why are there so many retransmissions for a particular application or host?"
The definitions of aborted, refused and ignored connections used by the TCP Health report:
Aborted — Connections were established, but were closed by a RST (reset) issued by either the client or server
rather than a clean close. High numbers of aborted connections can point to network or server problems.
Refused — A SYN packet was observed and a RST or ICMP "connection refused" message was received in response.
This usually means the server is up, but the application is unavailable or not working correctly. It can also indicate a TCP
port scan is occurring.
Ignored
— A SYN packet was observed, but no SYN-ACK response was received. This usually means the server is not
responding, does not exist, is not accessible, or is ignoring the connection request. It can also indicate a TCP port scan is
occurring.
VERSION INFO
A new internal mechanism was implemented in the ExOS 7.4.2 firmware that prevents Exinda Appliances from
being affected by DDoS attacks. As a consequence, the “Ignored Connections” historical report is no longer
available, but the Real Time TCP Health report still includes the number of ignored connections.