Cisco 2960S connection problem

[ahmetemrah]

Hi,

I have a Cisco 2960 S 24-TSL switch and a simple LAN of a few devices. I fail to connect to one of my devices from my PC both of which are connected to the switch. However, when I connect the PC and the device to another switch(unmanaged), or use a direct connection without using a switch there seems to be no problem.

[Martin Carr]

Ok, well that needed doing anyway, from what you have said I assume your device is statically configured?

The LED will be green as the interface is up.

Martin

[ahmetemrah]

You are right, the device is statically configured.

I tried another thing today. There are other 10 Mbps devices connected to the 2960S, and they work fine. I wondered why that's the case and investigated their response to tdr test and got this result:

Switch#show cable tdr interface GigabitEthernet1/0/11

TDR test last run on: March 06 10:30:01

Interface Speed Local pair Pair length        Remote pair Pair status

--------- ----- ---------- ------------------ ----------- --------------------

Gi1/0/11  10M   Pair A     1    +/- 0  meters N/A         Normal

                Pair B     2    +/- 0  meters N/A         Normal

                Pair C     2    +/- 1  meters N/A         Open

                Pair D     2    +/- 1  meters N/A         Open

As you can see the pair status is either normal or open. However, in the faulty device it was normal and short.

So, can pairs be "short" in a 10 Mbps connection? Do they need to be "open"? Or is it irrelevant?

[Martin Carr]

I do understand what you are saying, which is correct.

DHCP is not configured by default, so I suspect you are confusing it with something else!

That makes no difference though, it looks like the NIC has a physical problem, assuming when you say it was working, nothing has changed with the devices config.

Martin

[ahmetemrah]

I understand that the NIC may have a physical problem.

However as I stated before what's bugging me is that the device is working fine with other switches (unmanaged). I just unplug the ethernet cable and PC's cable and plug into other switches and I can connect to the device  without doing any configurations.

Here's something I tried:

I connected another switch (unmanaged) to 2960S. Connected to this unmanaged switch are PC (10.10.27.12) and the device (10.10.27.11). 

2960S can now ping 10.10.27.12 (PC), but not 10.10.27.11.

At the same time PC can ping 10.10.27.11.

So, the device has an IP adress, thus PC that is connected to the same switch can ping it.

However 2960S cannot reach the device although it can reach the PC.

[Martin Carr]

The device does not 'get' an IP, given it is statically configured.

Is your other switch Fast Ethernet?

Martin

[ahmetemrah]

You are right, but it was Leo's suggestion a few messages back that the device does not have a valid IP, so I wanted to make that point clear.

The other switch is Gigabit

but it works fine in fast ethernet too

[ahmetemrah]

Thank you for your assistance although we could not really find a solution.

Before leaving this thread, as a final question, I would like to ask if there is anything I can do to make the switch dumb? Close all settings/restrictions for that particular port (or all ports) so that 2960S would allow connecting to the device just like the 1Gbps unmanaged switch does?

[Martin Carr]

No, they are either one or the other.

If you don't configure an SVI you won't be able to connect to it remotely, but none the less, it's still a managed switch!

I was going to say, (although highly unlikely) is the device being blocked via STP?

Martin