[geeks] Network Nightmare

[md.benson at gmail.com]

Thankfully webre a small company site wise and I have a pretty tight grip on
the network (and the people using it xD). I am in and out if most areas
regularly and any unauthorised ethernet devices are confiscated on sight.

I had a quick scope around and canbt see any obvious loops or wiring
stupidity.

If I was to rip out the main switch in the middle and put in a low cost Cisco
or similar small business model (around B#200 inc Tax) would that give me
better accounting and tractability of the issue on itbs own or would I need
to replace all 3 of the main backbone switches?

As ever Ibm fighting up hill money wise and I know B#600 to pull all our
switches (given that the 2 outlying ones arenbt even 3 years old) is going
to get me some pretty hard looks, especially in light of That Thar
Pandemic(tm).

Thanks for the suggestions so far, itbs definitely something I need to take
up the ladder once I have an idea.

Sent from my iPhone

> On 20 Jul 2020, at 14:40, Mike Meredith <very at zonky.org> wrote:
>
> o;?On Mon, 20 Jul 2020 09:30:27 -0400, Nathan Raymond wrote:
>> Unplug network cables, then plug things in one at a time until the
>> problem recurs. You can often look at the activity lights and will
>
> If you have double wall sockets, look for where people have 'tidied' up
> unused network cables by plugging one end into one socket and the other
> to the other. It's a regular thing at $work (fortunately we have
> managed switches). STP (or more updated versions of the same) is the
> killer feature of managed switches - worth the price of admission to
> stop this sort of issue in its tracks.
>
> The other possibility (although I think that a loop is probably more
> likely) is that you've got a rogue dhcp server handing out "bad" IPs.
> Watch out for someone who has brought in a domestic router to attach
> more 'stuff' to the network. Or there's a conflicting IP using the same
> address as 'something important'.