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From the 'Polling Policy' drop down menu the previously configured polling policies will be available for assignment. Once finished click the 'Edit and Update Node' button at the bottom of the Edit Node window.
Verification
SNMP/WMI
In order to verify that the polling interval is occurring at the dictated frequency we can run a query against an applicable rrd file. Likely candidate rrd files for each type of polling are listed below.
- ICMP/Ping - /usr/local/nmis8/database/nodes/<node name>/health/reach.rrd
- SNMP - /usr/local/nmis8/database/nodes/<node name>/interface/<interface name>.rrd
- WMI - / /usr/local/nmis8/database/nodes/<node name>/health/WindowsProcessor.rrd
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The number to the far left is the Unix epoch timestamp that the sample was collected. Subtracting the time stamps between subsequent samples will provide the polling interval in seconds.
ICMP/Ping
In order to verity the ICMP/Ping polling frequency we can use tcpdump to observe how often echo requests are being send to the subject node.
| Code Block |
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[root@opmantek conf]# tcpdump -i eth0 -n host 10.10.1.1 and icmp and src 192.168.10.68
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
05:44:54.816359 IP 192.168.10.68 > 10.10.1.1: ICMP echo request, id 3732, seq 41, length 64
05:44:54.960055 IP 192.168.10.68 > 10.10.1.1: ICMP echo request, id 3732, seq 175, length 64
05:44:55.103830 IP 192.168.10.68 > 10.10.1.1: ICMP echo request, id 3732, seq 309, length 64
05:45:55.386408 IP 192.168.10.68 > 10.10.1.1: ICMP echo request, id 3903, seq 41, length 64
05:45:55.532386 IP 192.168.10.68 > 10.10.1.1: ICMP echo request, id 3903, seq 175, length 64
05:45:55.677146 IP 192.168.10.68 > 10.10.1.1: ICMP echo request, id 3903, seq 309, length 64 |
NMIS will send 3 echo requests each polling interval. Observe that the time difference between two sets of three requests is the desired interval.