Need Help Understanding performance graphs

[pspagnola]

I am just starting to use SNMP to gather data from servers and from network devices. One of my first network devices is a cisco switch C9500X. I am going to include some screenshots of the bandwidth graphs.

My questions:

Why do I see so many "0 Gb/s"? If this is because the traffic volume is very low, then why doesn't the units auto scale to Mb/s or Kb/s? Some of of the graphs show Gb/s and some show Mb/s so it must know how to do this.

I don't have 65 ports on this switch. "show interface status" on the switch shows 52 ports. Why does port 65 have significant traffic?

A CSV export showed some very small numbers for one of the graphs that show 0 Gb/s. Is this a good troubleshooting tool?

I read the KB article about debugging graphs, but it didn't seem to apply to my questions.

[pspagnola]

for got attachments in first post. here they are.

[ssax]

It's likely showing G because it's passing -l G when calling the plugin, please edit the service in Configure > Core Config Manager > Services and see if it's using -l G, -l M, -l K, -l B, or something else.

Code: Select all

[root@xid ~]# /usr/local/nagios/libexec/check_rrdtraf -h
check_rrdtraf v0.5

Usage:
 check_rrdtraf -f <rrd_file> -w <warning_pair> -c <critical_pair>
           [-v][-e expire_seconds] [-l label_units]
 check_rrdtraf (-V | --version)
 check_rrdtraf (-h | --help)

Options:
-h, --help
  Print detaiiled help screen
-V, --version
  Print version information
-v    Verbose output. Can be specified twice for more verbosity
-vv   More verbose output, same as -v -v
-f    Full path to RRD file to read data from
-w    Warning threshold <rate> or pair <incoming>,<outgoing>
-c    Critical threshold <rate> or pair <incoming>,<outgoing>
-e    Log age threshold (in seconds, 5min=300)
-l    Data display label, one of B,K,M or G

Notes:
-Warning and critical thresholds are MAX values,
 going above the threshold will trigger an alert.
-Labels and units for warning and critical values
 are determined by the -l argument (if specified):
 B=bps; K=Kbps; M=Mbps; G=Gbps
-If the -l switch is specified, input values are assumed to
 be in the same units as specified in the -l switch
-If the -l switch is not specified, output values are scaled
 appropriately, and input values are assumed to be in Kbps

If you have questions, please PM me a copy of your profile, you can download it from Admin > System Profile by clicking the Download Profile button so we can investigate further.

It's likely picking up port channels/vlans/etc for the other interfaces.

Thank you!

[pspagnola]

I do have a G. should I change that to M. Why are some M and some G?

M is for mbps and G is for gbps. Did the snmp wizard guess the speed of each port?

[ssax]

Correct, the wizard essentially autoadjusts based on the port speed.

You can set it to whatever you'd prefer. When you run the wizard when you select the ports there is a dropdown that let's you select Mbps, Gbps, Kbs, or bps if you want to adjust them while running the wizard.