C-D-A, yep yep. -- Espi
On Sun, Sep 22, 2013 at 6:56 PM, Kurt Buff <kurt.b...@gmail.com> wrote: > Well, I do remember reading a long time ago that traffic shouldn't go > through more than three switches on a LAN (was that referred to as the > diameter? I can't remember) - that pretty much matches the Cisco model > of core, distribution and access, as described here, among many other > places: > http://searchnetworking.techtarget.com/tip/Core-Distribution-and-Access > > On Sun, Sep 22, 2013 at 6:33 PM, Micheal Espinola Jr > <michealespin...@gmail.com> wrote: > > Personally speaking, I try to stick to it as well. I've noticed more > wonky > > things the more environments diverge from it. Technically speaking, that > > should not make sense - but this an unqualified opinion of mine. > > > > -- > > Espi > > > > > > > > On Fri, Sep 20, 2013 at 11:59 AM, Michael B. Smith < > mich...@smithcons.com> > > wrote: > >> > >> I still use it. > >> > >> > >> > >> Violate the rule at your peril. :P > >> > >> > >> > >> From: listsad...@lists.myitforum.com > >> [mailto:listsad...@lists.myitforum.com] On Behalf Of Jonathan Link > >> > >> > >> Sent: Friday, September 20, 2013 2:07 PM > >> > >> > >> To: ntsysadm@lists.myitforum.com > >> Subject: Re: [NTSysADM] Semi-OT: Network problem > >> > >> > >> > >> Is this the equivalent of Vader saying "Your powers are weak, old man" > to > >> Obi Wan? > >> > >> > >> > >> On Fri, Sep 20, 2013 at 1:55 PM, Kurt Buff <kurt.b...@gmail.com> wrote: > >> > >> Sigh. Yes, but... > >> > >> "The 5-4-3 rule was created when 10BASE5 and 10BASE2 were the only > >> types of Ethernet network available. The rule only applies to > >> shared-access 10 Mbit/s Ethernet backbones. The rule does not apply to > >> switched Ethernet because each port on a switch constitutes a separate > >> collision domain." > >> > >> :) > >> > >> Kurt > >> > >> On Fri, Sep 20, 2013 at 10:37 AM, Michael B. Smith > >> <mich...@smithcons.com> wrote: > >> > http://en.wikipedia.org/wiki/5-4-3_rule > >> > > >> > > >> > >> > -----Original Message----- > >> > From: listsad...@lists.myitforum.com > >> > [mailto:listsad...@lists.myitforum.com] On Behalf Of Kurt Buff > >> > >> > Sent: Friday, September 20, 2013 12:59 PM > >> > To: NTSysADM@lists.myitforum.com > >> > Subject: [NTSysADM] Semi-OT: Network problem > >> > > >> > All, > >> > > >> > In the past couple of weeks, $work has had a problem with network > >> > interruptions - frequent gaps in network connectivity were all > contact is > >> > lost with servers for brief periods of time (1-2 minutes, usually). > >> > > >> > I could see the gaps in the graphs on my (very new and incomplete - > long > >> > story, don't ask) cacti installation. Unfortunately, I've been unable > to get > >> > cacti to graph CPU utilization for the switches, because they're > Procurves, > >> > and I couldn't find a working XML file or configuration for that. > >> > > >> > It's always happened while I've been unavailable, until today. > >> > > >> > Just now, I was able to show conclusively that our core layer3 switch > >> > (Procurve 3400cl-48G), which was hit hardest, spikes its CPU to 99% > during > >> > these episodes. Volume of traffic is normal - ho huge spikes in that, > just > >> > normal variation, AFAICT, from the cacti graphs. I haven't had time > to see > >> > if other switches also spike their CPU, but given the gaps in the > graphs, I > >> > suspect that's the case. > >> > > >> > I suspect someone is doing something stupid to create layer2 loop, as > we > >> > have lots of little 5 and 8 port switches on desktops and in our > engineering > >> > lab - and in spite of the fact that I've set our core switch as the > root of > >> > the spanning tree. > >> > > >> > I'm setting up a box to do a tcpdump in a ring buffer with smallish > >> > files so that I can do analysis on them more easily. > >> > > >> > I'm not a packet analysis guy, though I've done some looking on > >> > occasion. > >> > > >> > Anyone have thoughts on what to look for when I start my analysis? > >> > > >> > Kurt > >> > > >> > > >> > >> > > > > > > >
