strange problem with cable modem connection

Hello,

I have a strange problem with my cable connection. All responsible people
are incapable or unwilling to search/solve the problem.

In my apartment house all flats share one 2GBit cable modem in the
following way:

LAN---Hub---Router---Cablemodem---Internet/ISP

In the beginning everthing worked fine. Then suddenly there were irregular
connection problems. The router is not reachable for a couple of seconds
(max ~20s). Neither from the inside nor the outside. My hardware is not the
problem, because you can see these effects from the outside even when I
pull my network cable. I use a linux firewall to protect my home network.

Those disconnects can occur once every half hour or more likely only a few
seconds/minutes appart. This is really annoying and there is no easy to see
mistake in the whole configuration. They exchanged the router already.
One idea would be an IP conflict. Maybe someone in the house configured his
PC with the IP of the Router. Could this cause these symptoms?

Can anybody give me some hints what the possible problem could be? It seems
that I have to tell the technicians every step :-(

Thanks,

Achim

Achim Keller wrote:
> Hello,
>
> I have a strange problem with my cable connection. All responsible people
> are incapable or unwilling to search/solve the problem.
>
> In my apartment house all flats share one 2GBit cable modem in the
> following way:
>
> LAN---Hub---Router---Cablemodem---Internet/ISP
>
> In the beginning everthing worked fine. Then suddenly there were irregular
> connection problems. The router is not reachable for a couple of seconds
> (max ~20s). Neither from the inside nor the outside. My hardware is not the
> problem, because you can see these effects from the outside even when I
> pull my network cable. I use a linux firewall to protect my home network.
>
> Those disconnects can occur once every half hour or more likely only a few
> seconds/minutes appart. This is really annoying and there is no easy to see
> mistake in the whole configuration. They exchanged the router already.
> One idea would be an IP conflict. Maybe someone in the house configured his
> PC with the IP of the Router. Could this cause these symptoms?
>
> Can anybody give me some hints what the possible problem could be? It seems
> that I have to tell the technicians every step :-(
>
> Thanks,
>
> Achim

if its one of those "broadband" routers than you probably need to step
up to a better model. They are notorious for going down when someone
dumps a lot of quick data across them. For instance when refreshing
servers list in GAmeSpy, the router can crash, sometimes requiring a
power cycle. You probably just need to purchase a better one.

--
Respectfully,


CL Gilbert

"Verily, verily, I say unto you, He that entereth not by the door() into
the sheepfold{}, but climbeth up some other *way, the same is a thief
and a robber." John 10:1

GnuPG Key Fingerprint:
82A6 8893 C2A1 F64E A9AD 19AE 55B2 4CD7 80D2 0A2D

For a free Java interface to Freechess.org see
http://www.rigidsoftware.com/Chess/chess.html

Achim Keller <(E-Mail Removed)> wrote in message news:<bvqsd1$bf7$(E-Mail Removed)>...
> Hello,
>
> I have a strange problem with my cable connection. All responsible people
> are incapable or unwilling to search/solve the problem.
>
> In my apartment house all flats share one 2GBit cable modem in the
> following way:
>
> LAN---Hub---Router---Cablemodem---Internet/ISP

Is the ISP aware that your connection to them is being shared in this way?
My Cable ISP won't support local nets.

John Culleton

John Culleton wrote:
>>LAN---Hub---Router---Cablemodem---Internet/ISP

> Is the ISP aware that your connection to them is being shared in this way?
> My Cable ISP won't support local nets.

Yes of course. This infrastructure belongs to the house. It's a modern
building with built-in LAN. Every party gets one or two static IPs. The big
advantage is, that there is no shaping. So if you are the only user, you
have the full bandwidth of the modem :-)

Achim

CL (dnoyeB) Gilbert wrote:

>>LAN---Hub---Router---Cablemodem---Internet/ISP

Modem: Kathrein DCM 30
Router: Zyxel Prestige 300 Series
Hub: Netgear EN516

> if its one of those "broadband" routers than you probably need to step
> up to a better model. They are notorious for going down when someone
> dumps a lot of quick data across them. For instance when refreshing
> servers list in GAmeSpy, the router can crash, sometimes requiring a
> power cycle. You probably just need to purchase a better one.

There is not much traffic over the router (except of my own). And in the
very beginning it worked fine. I don't know if they changed something when
the problems started. but they should know. Unfortunately the service is
crap, so I try investigate on my own.

I've been monitoring the problem for a long time. The connection also
breaks down every now and then, when I have a ping running every second to
the router.
But I have the impression, that when you start loading a web page (e.g.
overloaded portal) it can be triggered, as well as it can occur with
permanent streams (web radio).
Thanks to the Hub, I can see, that it also happens when nobody else is online.

The hardware is part of the infrastructure of our modern building. Every
flat has built-in network sockets. If you sign up for an Internet
connection you get a static IP.

Achim

Achim Keller wrote:
> CL (dnoyeB) Gilbert wrote:
>
>
>>>LAN---Hub---Router---Cablemodem---Internet/ISP
>
>
> Modem: Kathrein DCM 30
> Router: Zyxel Prestige 300 Series
> Hub: Netgear EN516
>
>
>>if its one of those "broadband" routers than you probably need to step
>>up to a better model. They are notorious for going down when someone
>>dumps a lot of quick data across them. For instance when refreshing
>>servers list in GAmeSpy, the router can crash, sometimes requiring a
>>power cycle. You probably just need to purchase a better one.
>
>
> There is not much traffic over the router (except of my own). And in the
> very beginning it worked fine. I don't know if they changed something when
> the problems started. but they should know. Unfortunately the service is
> crap, so I try investigate on my own.
>
> I've been monitoring the problem for a long time. The connection also
> breaks down every now and then, when I have a ping running every second to
> the router.

well thats what Gamespy does. it pings tons of servers in quick
succession. that hoses some of the broadband routers.

> But I have the impression, that when you start loading a web page (e.g.
> overloaded portal) it can be triggered, as well as it can occur with
> permanent streams (web radio).
> Thanks to the Hub, I can see, that it also happens when nobody else is online.
>
> The hardware is part of the infrastructure of our modern building. Every
> flat has built-in network sockets. If you sign up for an Internet
> connection you get a static IP.
>
> Achim


are you sure its the router thats going down?



--
Respectfully,


CL Gilbert

"Verily, verily, I say unto you, He that entereth not by the door() into
the sheepfold{}, but climbeth up some other *way, the same is a thief
and a robber." John 10:1

GnuPG Key Fingerprint:
82A6 8893 C2A1 F64E A9AD 19AE 55B2 4CD7 80D2 0A2D

For a free Java interface to Freechess.org see
http://www.rigidsoftware.com/Chess/chess.html

CL (dnoyeB) Gilbert wrote:

>>I've been monitoring the problem for a long time. The connection also
>>breaks down every now and then, when I have a ping running every second to
>>the router.
> well thats what Gamespy does. it pings tons of servers in quick
> succession. that hoses some of the broadband routers.

OK, I understand the GameSpy issue. But a single ping every second is not
considered as heavy traffic! Opening a website should also be in the range
of 'normal use'.

> are you sure its the router thats going down?

It could be the modem. The Cable company says, that it is working properly.
the router has the gateway IP. When I'm disconnected, this IP cannot be
pinged from neither sides. I assume, if the modem on the external side, or
the hub on the internal side would go down, you should be able to ping the
router from the opposite side at least.

Achim