Stupid SNMP error

[kaptk2]

First the vitals,

Cacti 0.8.6c with all the patches from the offical patches applied
OS: Linux Redhat EL

Next the problem:
I am trying to add some devices to cacti, I create the device and I always get an SNMP error in the uper left under the SNMP Information title. I have cacti working on 1 other device on my network so I am pretty sure it is an SNMP problem. But here is the weird thing I also have mrtg running until I can migrate fully over to cacti and it has no trouble grahing this exact same host. Both cacti and mrtg are running on the same box.

So what is the deal why can't cacti poll this device? I have debug output turned on and I don't see any error messages. What is wrong?

[rony]

Do you have snmp support enabled in Php?

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php -m

Will show you the modules, look for snmp.

If you do not have snmp modules installed, make sure that your paths to snmpget and snmpwalk are correct. If you don't have snmpget and snmpwalk installed, you will need the snmp-utils RPM to get them

[kaptk2]

Yes I do have the snmp module for php. I do think it is a snmp problem but cacti works great for the other device that I currently have graphing.

[SAS]

perhaps there is an access list on the SNMP device, if your cacti poller is different than the MRTG poller, it should be the problem. Use Getif, a SNMP client for resolve your problem.

[kaptk2]

No access list on the snmp device. Does anybody else have any ideas? This is driving me nuts. Do you need more info? If so what info do you need?

[rony]

Have you confirmed SNMP version? Is the device SNMPv1 or SNMPv2? Is it set correcly in cacti. From the cacti box, can you snmpwalk the device in question?

SNMPv1

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snmpwalk -v 1 -c <snmp community> <host>

SNMPv2

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snmpwalk -v 2c -c <snmp community> <host>

What version of snmpget and snmpwalk do you have installed,and what is your OS?

[kaptk2]

As stated above my OS Rehat Linux EL:
uname -r 2.4.21-15.0.4.EL

SNMP version:
# snmpwalk -V
NET-SNMP version: 5.0.9

The device in question is a smartbrige Airpoint Pro. It uses snmp v1. I can snmpwalk the device in question with some help ie:

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snmpget -v 1 -c password ipaddress .1.3.6.1.4.1.410.1.2.1.1.0

More troubleshoot tips?

[rony]

Need to see the snmpwalk of the ".iso.org.dod.internet.mgmt.mib-2.system". Run the following command and post the output:

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snmpwalk -v 1 -c <snmp community> <host> .1.3.6.1.2.1.1

I want to make sure it's returning the information that cacti is looking for.

[kaptk2]

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snmpwalk -v 1 -c password ipaddr .1.3.6.1.2.1.1
Timeout: No Response from ipaddr

So that is a problem I think, but like I said mrtg can graph this host no problem.

[TheWitness]

As long as you can poll sysUptime, and are using cmd.php or the beta cactid, you should still be able to create graphs and poll the device.

TheWitness

[kaptk2]

As long as you can poll sysUptime, and are using cmd.php or the beta cactid, you should still be able to create graphs and poll the device.

How do I check that I can do such things?

Here is the debug from the data SNMP interface statistics query:

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+ Running data query [1].
+ Found type = '3' [snmp query].
+ Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/interface.xml'
+ XML file parsed ok.
+ Executing SNMP walk for list of indexes @ '.1.3.6.1.2.1.2.2.1.1'
+ No SNMP data returned
+ Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/interface.xml'
+ Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/interface.xml'
+ Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/interface.xml'

[rony]

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snmpwalk -v 1 -c password ipaddr .1.3.6.1.2.1.1
Timeout: No Response from ipaddr

So that is a problem I think, but like I said mrtg can graph this host no problem.

You have checked it. That OID should yield system related information via SNMP. Cacti uses this information, for polling (sysUptime) and for the host editor (the SNMP error you are getting at the top).

At this point, even if you got the OID's in question working, cacti would think the host is down and not poll it. This is where MRTG wouldn't care and happy attempt to poll the device and get the data.

Solutions, well, alter the method that cacti uses to detect host down, (not completely reliable), or attempt to enable SNMP information on the device in question. IE, sysContact, sysDescription, sysUptime, etc in that OID I listed before.

[kaptk2]

The device in question I found after some searching does not support the way cacti polls it to see if it is up. That is kinda a big bummer but nothing can really be done about it.

At this point, even if you got the OID's in question working, cacti would think the host is down and not poll it. This is where MRTG wouldn't care and happy attempt to poll the device and get the data.

Solutions, well, alter the method that cacti uses to detect host down, (not completely reliable), or attempt to enable SNMP information on the device in question. IE, sysContact, sysDescription, sysUptime, etc in that OID I listed before.

No way to enable that SNMP information, where can I find more info about changing the method caci uses to detect host down?

[rony]

You can change it in the settings. But I have had problems with it in the past, try and see. That is the only think I can suggest.

Settings -> Poller -> Downed Host Detection

[kaptk2]

Changed to ping only. That seems to do the trick I have graphs!!!

What gothca's do I have to worry about with ping only?

Also there is an snmp / ping option. If one does not respond (say snmp) will it fall back to ping and if ping reports it up is it assummed up or down?

Thanks for help getting this working!