Date: Tue, 5 Jan 2021 12:39:03 +0300 From: Victor Gamov <vit@otcnet.ru> To: freebsd-net@freebsd.org Subject: Re: 'dropped due to full socket buffers' by SNMP Message-ID: <888c8e91-c8f2-ad4b-9fcf-64c09432f2d5@otcnet.ru> In-Reply-To: <7e51a6be-aea1-51c6-c0bd-10d00c19d5d3@grosbein.net> References: <388da9a7-7b89-89b2-54eb-17d0e818c924@otcnet.ru> <4e41c1d2-19bc-0345-0b03-526e4cb785c7@otcnet.ru> <b279e676-c789-2978-98a0-b8a4b164a111@grosbein.net> <a69d872a-f21e-de66-7677-58beccb0f023@otcnet.ru> <6c780827-e764-8053-356b-a921e0892c15@grosbein.net> <fef04bda-6aa0-4a80-8999-867b9f37d766@otcnet.ru> <7e51a6be-aea1-51c6-c0bd-10d00c19d5d3@grosbein.net>
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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
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