We have a few very old dlink switches in our collection which won’t poll properly with snmpbulkwalk so approximately 6 months ago I added the nobulk override for dlink switches in config.php:
$config['os']['dlink']['nobulk'] = 'true';
This was tested and confirmed working at the time I added it, allowing even our oldest switches to successfully poll and provide port statistics. (As a side effect it also actually reduced poller time, which seems odd, but I’ll take it)
However I’ve just noticed a couple of the affected switches are no longer producing port traffic data graphs again, and when I check it seems the nobulk override in config.php is not working anymore. For example if I manually do a poller or discovery capture through the GUI I see lines like this showing that snmpbulkwalk is being used when it shouldn’t be:
Timeout: No Response from udp:10.0.2.6:161 SNMP['/usr/bin/snmpbulkwalk' '-v2c' '-c' 'COMMUNITY' '-OQUs' '-m' 'IF-MIB' '-M' '/opt/librenms/mibs:/opt/librenms/mibs/dlink' '-t' '5' '-r' '2' 'udp:HOSTNAME:161' 'ifName'] Exitcode: 1 Timeout: No Response from udp:10.0.2.6:161 Timeout: No Response from udp:10.0.2.6:161 SNMP['/usr/bin/snmpbulkwalk' '-v2c' '-c' 'COMMUNITY' '-OQUs' '-m' 'IF-MIB' '-M' '/opt/librenms/mibs:/opt/librenms/mibs/dlink' '-t' '5' '-r' '2' 'udp:HOSTNAME:161' 'ifAlias'] Exitcode: 1 Timeout: No Response from udp:10.0.2.6:161
Because this model of switch doesn’t like certain snmpbulkwalk queries it times out and no data is returned.
Another weird aspect to this issue is that although the affected switches were previously generating port traffic graphs with snmpbulkwalk disabled, (as I know for sure that every switch on our network was) not only is it not currently generating port traffic, all historical port traffic for the switch is completely gone as if it had never been there. (Ports, bits has no graphs)
I’m going to take a wild guess here and say that because certain snmpbulkwalk requests are failing during the discovery polling, LibreNMS might now believe that this switch doesn’t have any port data available to use and has therefore removed the graphs ?
Has anyone else noticed a problem with the nobulk option no longer working from config.php?
Can anyone confirm that using the nobulk option for a brand of switch should prevent the use of snmpbulkwalk for ALL discovery and poller queries not just some of them ?