Thanks Nick & Tim, This is awesome! i will get back to you after my deployment.
On Wed, Mar 20, 2019 at 1:34 PM Nick Cutting <[email protected]> wrote: > > We use the below, and I measured the reported traffic a few times, sending > exactly 1g / 10g files between a known source and destination; it was pretty > accurate. > > You must use routed ports, SVI’s require netflow – which is not an option for > you. > > > > feature sflow > > sflow counter-poll-interval 30 > > sflow collector-ip 10.x.x.x vrf default source 10.x.x.x.x > > sflow collector-port 6344 (match the NFSEN listening port) > > sflow agent-ip x.x.x.x (this switch’s loopback match the source/vrf above) > > sflow data-source interface Ethernet1/51 > > sflow data-source interface Ethernet1/52 > > > > its Bi-directional so we only do north facing ports in leaf/spine > > > > then the matching entry on NFSEN’s conf file is: > > > > %sources = ( > > ‘HOSTNAME’ => { 'port' => '6344', 'IP' => '10.x.x.x, 'col' => > '#0000ff', 'type' => 'sflow' } > > ); > > From: Satish Patel <[email protected]> > Sent: Wednesday, March 20, 2019 1:23 PM > To: Tim Stevenson (tstevens) <[email protected]> > Cc: Nick Cutting <[email protected]>; [email protected] > Subject: Re: [c-nsp] Nexus 9300 sflow performance > > > > This message originated from outside your organization. > > Thanks Tim, > > Here is the output of show hardware rate-limiter. ( i believe it's 40k) > > This is my first time dealing with SFLOW, Can you share some > configuration parameter i should use for best practice would be great, > What is 1-in-N sample actually? > > I am planning to use mgmt0 interface for SFLOW and its 1G so i assume > it will handle all the flow. do you seeing any concern there? > > > # show hardware rate-limiter > > Units for Config: packets per second > Allowed, Dropped & Total: aggregated since last clear counters > > > Module: 1 > R-L Class Config Allowed Dropped Total > +------------------+--------+---------------+---------------+-----------------+ > L3 glean 100 0 0 0 > L3 mcast loc-grp 3000 0 0 0 > access-list-log 100 0 0 0 > bfd 10000 0 0 0 > exception 50 0 0 0 > fex 3000 0 0 0 > span 50 0 0 0 > dpss 6400 0 0 0 > sflow 40000 25134089890 0 25134089890 > > On Wed, Mar 20, 2019 at 12:07 PM Tim Stevenson (tstevens) > <[email protected]> wrote: > > > > Yes, this is 1st gen. The SFLOW/SPAN restriction should not apply there. > > > > Re: 60Gbps/24Mpps and SFLOW, SFLOW does not do aggregation of stats for > > flows in the switch like netflow does - it's just 1-in-n packet sampling. > > As such, the value of "n" should be high enough that both the switch & the > > collector are not overburdened. Note that we will rate limit SFLOW copies > > to the CPU so that's the first 'bottleneck'. If you end up tail-dropping > > samples, the statistical validity of your sampled set goes out the window, > > so you want to ensure that 1-in-n is a number that does not hit that rate > > limiter. > > > > I don't have a 1st gen switch handy to see what the defaults are for that > > value. It should show up in 'sh hardware rate-limiter'. In 9300-EX with > > 9.2.2 it's 40Kpps. > > > > Beyond that, you also want to make sure the collector is able to consume > > everything coming from all sflow enabled switches without dropping, for the > > same reason mentioned above. > > > > Hope that helps, > > Tim > > > > > > -----Original Message----- > > From: Satish Patel <[email protected]> > > Sent: Wednesday, March 20, 2019 8:40 AM > > To: Nick Cutting <[email protected]> > > Cc: Tim Stevenson (tstevens) <[email protected]>; [email protected] > > Subject: Re: [c-nsp] Nexus 9300 sflow performance > > > > We have cisco Nexus9000 C9396PX > > > > 60 Gbs is data traffic, and 24Mpps ( packet per second ) not sure how > > to convert it into flows. Could you please share your sflow > > configuration if you don't mind? > > > > I had nfsen in past with 8CPU / 4GB memory but it was damn slow :( > > but it could be me.. i will set up again and see if it worth it or > > not. > > > > On Wed, Mar 20, 2019 at 11:34 AM Nick Cutting <[email protected]> wrote: > > > > > > Good point. We waited for the second Gen > > > > > > Regarding 60 Gbs, isn’t that is the data traffic, not the flows or > > > sampled flows levels? > > > > > > Our NFSEn box is centos > > > > > > 4 vCPU and 4 GBrams > > > > > > Collecting flows from maybe only 30 devices, about 20Gbs and 3k flows per > > > sec. > > > > > > -----Original Message----- > > > From: Tim Stevenson (tstevens) <[email protected]> > > > Sent: Wednesday, March 20, 2019 11:20 AM > > > To: Nick Cutting <[email protected]>; Satish Patel > > > <[email protected]>; [email protected] > > > Subject: RE: [c-nsp] Nexus 9300 sflow performance > > > > > > This message originated from outside your organization. > > > > > > Make sure you distinguish between N9300 (1st generation) and > > > N9300-EX/FX/FX2 (2nd generation). The SFLOW + SPAN limitation applies > > > only to the latter. It's also on the latter that Netflow is supported, > > > which can run concurrently with SPAN sessions. > > > > > > Tim > > > > > > -----Original Message----- > > > From: cisco-nsp <[email protected]> On Behalf Of Nick > > > Cutting > > > Sent: Wednesday, March 20, 2019 6:19 AM > > > To: Satish Patel <[email protected]>; [email protected] > > > Subject: Re: [c-nsp] Nexus 9300 sflow performance > > > > > > We use sflow on 9300's, no performance hit - but you cannot use span > > > sessions at the same time. > > > > > > Newer code revisions support netflow, without the SPAN session > > > limitation, although we have not tried netflow on the 9300 yet. > > > > > > For a collector We use NFSEN - opensource, and quite a big install base, > > > and it seems to handle a lot of flows. > > > > > > It supports sflow and netflow as we have a mix, just make sure you add > > > the sflow option at build time as it’s a bit funky old linux to add it > > > after. > > > > > > > > > > > > -----Original Message----- > > > From: cisco-nsp <[email protected]> On Behalf Of Satish > > > Patel > > > Sent: Wednesday, March 20, 2019 8:21 AM > > > To: [email protected] > > > Subject: [c-nsp] Nexus 9300 sflow performance > > > > > > This message originates from outside of your organisation. > > > > > > Folks, > > > > > > I have L3 Nexus 9300 switch which is running 60Gbps traffic on ISP > > > interface so I’m planning to run sflow on that specific interference to > > > get flow. > > > > > > Does it going to create any performances issue on switch? > > > > > > Can I run sflow on Layer 3 LACP interface? > > > > > > Can anyone suggest free open source sflow collector? > > > > > > Sent from my iPhone > > > _______________________________________________ > > > cisco-nsp mailing list [email protected] > > > https://puck.nether.net/mailman/listinfo/cisco-nsp > > > archive at http://puck.nether.net/pipermail/cisco-nsp/ > > > > > > _______________________________________________ > > > cisco-nsp mailing list [email protected] > > > https://puck.nether.net/mailman/listinfo/cisco-nsp > > > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
