Comments on: How To Monitor Network Switch and Ports Using Nagios

By: Chitti Prasad

Chitti Prasad — Sat, 24 Dec 2011 08:01:14 +0000

In Steps #6 and #7 – to monitor switch ports, the Port Number given in the service command i.e., “ifOperStatus.1″ <== the 1 is not always the switch port number. The port number for different switches will be different – for example for Cisco2960 Gigabit switch, it will start at 10101 for the first port. It is better to run a snmpwalk command on the switch with "ifDescr" as OID as below for a switch with ip address 172.16.16.1:
#snmpwalk -v 1 -c public 172.16.16.1 ifDescr
IF-MIB::ifDescr.1 = STRING: Vlan1
IF-MIB::ifDescr.10101 = STRING: GigabitEthernet0/1
IF-MIB::ifDescr.10102 = STRING: GigabitEthernet0/2
IF-MIB::ifDescr.10103 = STRING: GigabitEthernet0/3
IF-MIB::ifDescr.10104 = STRING: GigabitEthernet0/4
IF-MIB::ifDescr.10105 = STRING: GigabitEthernet0/5
.
.
.
The number foloowing "ifDescr" in the output above is the actual switch port number. As displayed in the first line, the "ifDescr.1" denotes "Vlan1" – which can be taken as the total switch itself – thus it can be used to get the status of the sitch as a whole!

By: 7 Steps to Upgrade IOS Image on Cisco Catalyst Switch or Router

7 Steps to Upgrade IOS Image on Cisco Catalyst Switch or Router — Thu, 23 Jun 2011 06:04:03 +0000

[...] On a side note, you should be using some software to monitor your switch status. If you are not doing it install Nagios, and monitor your switches. [...]

By: PT

PT — Wed, 11 May 2011 22:13:16 +0000

Is it possible to use check_mrtgtraf if the server running mrtg is a windows server? In my environment I have mrtg running on a windows 2000 box.

By: ramesh

ramesh — Fri, 24 Dec 2010 07:35:23 +0000

hi experts,

hi iam configuring nagiios monitoring for but i’m confusing about web access..
so can you please suggest me how would it be please,

regards,
ramesh.

By: Jay

Jay — Mon, 27 Sep 2010 18:34:17 +0000

Hoping someone can help me here. I am currently running Nagios Core Version 3.2.1 and am having an issue monitoring ports on my Cisco 3750 switches. Currently I have all of my switches setup within a host group and can see all other data with the exception of port status. I followed the directions from this site on how to set it up, but to no avail. For instance, I keep getting the error “External command error: Error in packet” and it shows a status of UNKNOWN. What’s strange is that I also have a monitor setup on port 1 (Port 1 Link Status) and it shows as green, but yet the port is in down/down status within the switch. Here is my syntax:

check_snmp! -C -o ifOperstatus.4 -r 1 -m RFC1213-MIB

Any help would be greatly appreciated.

-Jay

By: Vaibhav Mishra

Vaibhav Mishra — Thu, 23 Sep 2010 08:05:07 +0000

Hi Experts,

Can I request for some suggestion for my query as below? I have NAGIOS 3.2 installed on Red Hat Enterprise Linux AS release 4. When I try to monitor traffic on a particular port of my router (router support SNMP), I get Return code of 255 is out of bounds.

I learnt that my OS should have NET:SNMP agent installed. When I checked, I found that NET::SNMP agent installed as you can see below the output.

rpm -qa | grep net-snmp
net-snmp-devel-5.1.2-11.EL4.6
net-snmp-5.1.2-11.EL4.6
net-snmp-utils-5.1.2-11.EL4.6
net-snmp-perl-5.1.2-11.EL4.6
net-snmp-libs-5.1.2-11.EL4.6

Can some one tell me where I am making a mistake or if the NET::SNAMP agent need some customization?

Your kind help must be appreciated.

Regards,

Vaibhav

By: David Merrick

David Merrick — Mon, 28 Jun 2010 23:50:18 +0000

@baggage and @sawsen–
I’m no expert, and am still trying to get mrtg working myself, but most tutorials on how to install mrtg have you put the log files in /var/www/mrtg.

Instead of:
check_local_mrtgtraf!/var/lib/mrtg/192.168.1.11_1.log!AVG!1000000,2000000!5000000,5000000!10

You might try:
check_local_mrtgtraf!/var/www/mrtg/192.168.1.11_1.log!AVG!1000000,2000000!5000000,5000000!10

(Notice the /var/www instead of /var/lib)
~David

By: baggage

baggage — Fri, 23 Apr 2010 09:55:21 +0000

Can you take a look at this, please?
Or Can somebody tell me how to add a switch monitoring on nagios3 without centreon interface?
Actually, I mean about the services since i’ve added the switch. =)
But I would like to monitor it’s Bandwidth Usage and CPU load/stats.
I did sth like the following :

- Bandwidth/traffic :
Error message is : Port 1 Bandwidth Usage CRITICAL(Return code of 139 is out of bounds)

define service{
use generic-service
host_name switch1
service_description Port 1 Bandwidth Usage
check_command check_mrtg!10.4.126.234_1.log!1!1000000!1500000!In!Bytes/Sec
# check_command traffic_average!10.4.126.234 10 !AVG 1000000 2000000 5000000 5000000
}

along with the following given command in /etc/nagios-plugins/config/mrtg.cfg :

# ‘check_mrtg’ command definition
define command{
command_name check_mrtg
command_line /usr/lib/nagios/plugins/check_mrtg ‘$ARG1$’ 10 AVG ‘$ARG2$’ ‘$ARG3$’ ‘$ARG4$’ ‘$ARG5$’ ‘$ARG6$’
}

# ‘traffic_average’ command definition
define command{
command_name traffic_average
command_line /usr/lib/nagios/plugins/check_mrtgtraf ‘$ARG1$’ 10 AVG ‘$ARG2$’ ‘$ARG3$’ ‘$ARG4$’ ‘$ARG5$’
}

- CPU stats :
Erro message : Port2CPUstats snmp_cpustat -> UNKNOWN : External command error: Cannot find module (”): At line 1 in (none)

define service{
hostgroup_name Switches
use generic-service
service_description Port2CPUstats snmp_cpustats
check_command snmp_cpustats!public!50
}

along with the following given command definition in /etc/nagios-plugins/config/snmp.cfg:

# ‘snmp_cpustats’ command definition
define command{
command_name snmp_cpustats
command_line /usr/lib/nagios/plugins/check_snmp -H ‘$HOSTADDRESS$’ -C ‘$ARG1$’ -o .1.3.6.1.4.1.2021.11.9.0,.1.3.6.1.4.1.2021.11.10.0,.1.3.6.1.4.1.2021.11.11.0 -l ‘CPU usage (user system idle)’ -u ‘%’
}

For instance, I really abandon centreon matter because it’s a kinda “urgent” project for me. :s
for mrtg, do we need to install it? That’s kinda what i got from googling. :/

Thanks,

kpwstarina@yahoo.com

By: sawsen

sawsen — Tue, 01 Dec 2009 11:37:40 +0000

Hi,
Always i have: check_mrtgtraf: Impossible d’ouvrir le fichier de log de MRTG
In the configuration of switch I have:
check_command check_local_mrtgtraf!/var/lib/mrtg/192.168.1.253_1.log!AVG!1000000,1000000!5000000,5000000!10
but in var/lib/mrtg i don’t have a file 192.168.1.253_1.log
Can someone help me?
thank you in advance

By: Norman Paterson

Norman Paterson — Mon, 30 Nov 2009 15:38:13 +0000

Where is the mapping between snmp port numbers and switch port numbers defined? It’s simple enough for the first 24 ports, but my 2950 then has two more ports labelled 1 and 2 (ie duplicating the first 2 port numbers). If I use snmpwalk to see what ports are being monitored, I get 28 in all:

# snmpwalk -v1 -c public my_switch -m ALL .1 | grep ifOperStatus
RFC1213-MIB::ifOperStatus.1 = INTEGER: down(2)
RFC1213-MIB::ifOperStatus.2 = INTEGER: down(2)
RFC1213-MIB::ifOperStatus.3 = INTEGER: down(2)
…
RFC1213-MIB::ifOperStatus.26 = INTEGER: down(2)
RFC1213-MIB::ifOperStatus.27 = INTEGER: up(1)
RFC1213-MIB::ifOperStatus.28 = INTEGER: up(1)

I’ve not been able to find this information from the usual sources (ie Google, Cisco).