Lights flashing on hub

Hi all,

I have a couple of machines connected to an 8 port hub. Yesterday
everything was working fine. Unfortunately today none of my machines can
see eachother. What does it mean if all the lights on the hub are flashing
constantly? I don't have the manual for the hub, so I can't identify what
the problem may be.

Thanks.

M Jones left a note on my windscreen which said:

> Hi all,
>
> I have a couple of machines connected to an 8 port hub. Yesterday
> everything was working fine. Unfortunately today none of my machines can
> see eachother. What does it mean if all the lights on the hub are flashing
> constantly? I don't have the manual for the hub, so I can't identify what
> the problem may be.
>
> Thanks.

It probably depends on the hub in question. Usually a flashing LED
shows network traffic but depending on the hub it could mean packet
collisions.

I would begin by checking the network setting on both machines. Correct
IP's? Subnet mask etc.? Can your machines ping each other at all?

Have you tried using a crossover cable to connect the two PCs together
without the hub?
--

Stoneskin

[Insert sig here]

In message <bqho8p$7jr$(E-Mail Removed)>, M Jones
<(E-Mail Removed)> writes
>Hi all,
>
>I have a couple of machines connected to an 8 port hub. Yesterday
>everything was working fine. Unfortunately today none of my machines can
>see eachother. What does it mean if all the lights on the hub are flashing
>constantly? I don't have the manual for the hub, so I can't identify what
>the problem may be.

There may be more than one sort of light, one for link activity and
another for collisions. If the collision light flashes it means two
nodes have tried to send at the same time. If the collision light is
flashing a lot then your network is overloaded. The collision light is
likely to be yellow or red.

There are three possible problems. One is that some software you have
installed is creating a lot of network traffic.

The second is that software someone else installed (possibly a virus or
worm) is sending a lot of network traffic.

The third is that there is a hardware problem.

First disconnect your network from the Internet. Do that now. If that
stops the problem then suspect a virus, or perhaps some authorised
software downloading stuff from the Internet. See if there is an error
message on the screen anywhere.

If the problem continues then disconnect each machine in turn. Reboot
that machine but go into the BIOS setup screen. I don't think the
network card should be sending any traffic at that point. If it's still
sending then a hardware problem sounds most likely.




--
Bernard Peek
London, UK. DBA, Manager, Trainer & Author. Will work for money.

In article <bqho8p$7jr$(E-Mail Removed)>,
(E-Mail Removed), a.k.a M Jones says...


> I don't have the manual for the hub

But you do have the make/manufacturer/model no.
Maybe?

On Tue, 02 Dec 2003 10:07:23 +0000, M Jones wrote:

> Hi all,
>
> I have a couple of machines connected to an 8 port hub. Yesterday
> everything was working fine. Unfortunately today none of my machines
> can see eachother. What does it mean if all the lights on the hub are
> flashing constantly? I don't have the manual for the hub, so I can't
> identify what the problem may be.
>
> Thanks.


A hub is a pretty thick peice of kit, it either works or it doesn't. Your
problem could be the hub itself or one of your network cards. Don't mess
up your network settings, this is more than likely a hardware problem.

First power cycle the hub. Is it still the same?

Unplug the Cat5 cables one at a time. Is one of the cables causing the
problem?

Re-connect everything. Has the problem gone away?

If not the chipset in the hub has probably lost the plot! Some cheap
hubs (about 1-2 years old) run very hot and burn them selves out.
The new ones don't have this problem and an 8 port hub costs about a
tenner. So don't be upset if the hub is dead.

Graham.

if it's a regular flash... say once twice per second it usually means
an error... on the more dumb and inexpensive hubs this usually means
'knackered'

take the cables out one by one to see if that stops it, if one cable
seems to be the problem then check the cable and the device attached
to it as you may have a bad network card.

Dex

On Tue, 2 Dec 2003 10:07:23 +0000 (UTC), "M Jones"
<(E-Mail Removed)> wrote:

>Hi all,
>
>I have a couple of machines connected to an 8 port hub. Yesterday
>everything was working fine. Unfortunately today none of my machines can
>see eachother. What does it mean if all the lights on the hub are flashing
>constantly? I don't have the manual for the hub, so I can't identify what
>the problem may be.
>
>Thanks.
>
>
>