'dropped due to full socket buffers' by SNMP

[Eugene Grosbein]

05.01.2021 16:39, Victor Gamov wrote:

>>> As I understand hw.ix.flow_control=3 to allow flow-control for negotiation.
>>> Real PAUSE setting will be set during negotiation.
>>
>> At the moment of congestion.
> 
> As I understand PAUSE feature negotiated during auto-negotiation process. If flow-control disabled on one side (switch for example) then other side (host) will not to use this feature too.  Is it right?

Modulo firmware bugs.

>>>   So where I can find active flow-control setting for host interface?
>> Can't check for ix just now, but for em(4) there is sysctl dev.em.0.fc.
>> It should be similar for ix.
> I have hw.ix.flow_control=3 (what does is it means ?) and dev.ix.0.fc=3 (and what does is it means?)

/* Flow Control Settings */
enum ixgbe_fc_mode {
        ixgbe_fc_none = 0,
        ixgbe_fc_rx_pause,
        ixgbe_fc_tx_pause,
        ixgbe_fc_full,
        ixgbe_fc_default
};

So, ixgbe_fc_full = 3 (full rx/tx flow control enabled, see sys/dev/ixgbe/ixgbe_type.h).
 
> Back to my original question: is it possible to monitor `netstat -n -p udp -f inet -s` counters by SNMP?

There is no standard MIB for these counters but you may always export it with net-mgmt/bsnmp-ucd port
and custom OIDs if you use stock bsnmpd (bsnmp-ucd man page has an example).
There is similar possibility for net-snmpd.