It seems that in my case - looping LAN1 with LAN2 and sending/receiving WAN<-->WLAN3 traffic leads to no visible traffic degradation. That probably mean that I failed to create lan loop.
The lights were "kind of" busy on LAN1 <--> LAN2, but the wlan3 and upstream WAN are slow enough to observe any effect on that traffic. I will try to gather together 8+ switches when I get home after the New Year. With that I may be able to observe some traffic pattern change when crossing switching depth 7. > The router/switch looks this way: > - WAN (eth0) > +- LAN1 (eth1) > +- LAN2 (eth2) > +- WLAN3 (wlan0) > The router is running openWrt. > Tomas On Wed, 2019-12-25 at 09:15 -0800, Mike C. wrote: > > > > I happened to have a netgear FS105 nearby. Plugging in a laptop to a switch > > port, and plugging a patch cable between two other switch ports and pinging > > a random ip address from the laptop set off the broadcast storm. Running > > tcpdump from the laptop showed a bunch of "MPCP, Opcode Pause, length 46" > > packets. Unplugging the loop, the packets stop immediately. > > > > The reason this works and why I suspect it won't work on the OPs router is > the Netgear isn't a 802.1D (Spanning Tree Compliant) switch. Those > multicast packets are flow control packets and would not be forwarded out > all switch ports downstream as per 802.1D they're reserved to be acted upon > only by the switch. > _______________________________________________ > PLUG mailing list > PLUG@pdxlinux.org > http://lists.pdxlinux.org/mailman/listinfo/plug _______________________________________________ PLUG mailing list PLUG@pdxlinux.org http://lists.pdxlinux.org/mailman/listinfo/plug
