Les Mikesell wrote: > On Wed, Feb 6, 2013 at 11:19 AM, SilverTip257 <silvertip257 at gmail.com> > wrote: >> >> If one of your hosts intermittently loses connectivity, the switch will >> broadcast that traffic to all ports because it can't find the host's MAC >> address. >> >> (And what Les said about the switch broadcasting traffic until it learns >> MAC addresses.) > > Some spanning tree events will force the switch to re-learn MACs too. I should have mentioned this switch is *only* in use on our subnet, though of course we go through it to go Out There, there are gov't firewalls outside of it. All the traffic is only on our subnet, in this case, and the weirdness was intermittent. At the time, there were two heavy users (me, doing an offline backup, from one room to another, the latter with the server being hit by me in it, and at that switch, and another user doing heave scientific computing). That is, of course, in addition to all the other normal traffic from dozens of other servers. Btw, he's not seeing it today, but I'm not running any more backups just now.... mark "gigabytes and gigabytes... of backup"