'dropped due to full socket buffers' by SNMP

[Victor Gamov]

Hi Eugene!

Thanks for your responces.

And Happy New Year for everyone!

On 01.01.2021 03:19, Eugene Grosbein wrote:
> 30.12.2020 23:08, 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?

>>   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?)


>>> maybe increase kern.ipc.maxsockbuf and then net.inet.udp.recvspace.
>> Eugene, at first message you suppose Host-A (sender) "outgoing link for that UDP packets is congested"
>> because this host shows non-zero "dropped due to full socket buffers".
>> So is net.inet.udp.recvspace increasing on Host-B (mainly receiver) will be affected for this congestion?
> 
> Can't tell in details without going deep into your setup :-)
> You can try it yourself and verify quickly.
>
>> Or I need to try to increase both kern.ipc.maxsockbuf and net.inet.udp.recvspace on both hosts?
> 
> Tune one that drops UDP.
> 
>> Also how I can check current sockbuf usage?
> 
> netstat -xn

Unfortunately it never shoes counters about UDP multicast traffic.

I'll increase kern.ipc.maxsockbuf and net.inet.udp.recvspace at next 
week and write about results.


Back to my original question: is it possible to monitor `netstat -n -p 
udp -f inet -s` counters by SNMP?


--
CU,
Victor Gamov