>> And to ask you who else has come across the danger to corporate
>> networks posed by the convenience of auto-crossover ports.
> I had this at a middle school I do work for, One little darling student
> did exactly this.
<snip>
> It is annoying that such a thing can happen, but to be honest it's no
> worse than in the old days of a missing t-piece or a cable fault,
> bringing down a whole coax lan.
True, those were the days. But the Base-T system has been so comparatively
rock-solid reliable and proof against all the problems we used to have
that it has been a shock to find that it is so easily compromised. And the
problem has only arisen with the more recent equipment!
> You should be using spanning tree protocol (sometimes called spamming
> tree protocol when it breaks) which should allow these kind of redundant
> links that you are creating. Indeed redundant links should be/are a good
> thing.
Yes, redundant links are, I am building up a number, and I have looked at
STP. The main reason I haven't used it is that I prefer the idea of
subnets, routed, RIP and routers instead: routers based on multi-port
FreeBSD boxes. I don't see how STP (or subnets) cure this switch-jamming
problem, except that the more intelligent the device the more capable it
is of preventing the jam from spreading back onto the network spine.
However, we have some quite large (multi-building) branches containing
hundreds of outlets that are all within the same easily-jammed area.
Luckily I don't yet have a large number of auto MDI/MDIX switches and am
hoping to obtain more older models, which are immune to this problem
because normal users don't possess crossover leads.
--
Christopher Dawkins, Felsted School, Dunmow, Essex CM6 3JG
01371-822698, mobile 07816 821659 cchd(a)felsted.essex.sch.uk