SG300-28P GBIC Port Not Transmitting

[indigo]

The switch has been set to Level 3 Routing.  Port 27 has been in use as a Fiber Transceiver with no problems for several weeks. This week I tried connecting a second Fiber Transceiver to Port 28, and it would not work.

Swapped the physical GBIC modules in the ports, and the situation remained exactly the same: Port 27 works, Port 28 would not work.

Connected to the copper-part of the combo Port 28, it immediately connected and worked fine.

Connected an external Fiber Transceiver Box in place of the GBIC in Port 28, and it immediately connected and worked fine.

Swapped the new Fiber jumper (Port 28) with the existing Fiber jumper (Port 27), and the new connection came up immediately and worked fine.  The existing connection would not work when connected to Port 28.

By "not working", I am not able to ping across the connection.  The link light comes on and blinks.  The transmit/receive statistics show as if data is processing on this switch, but on the other side of the Port 28 connection, the switch shows Transmit traffic, but no Recieve traffic.

Any ideas what I should try next?   The only thing I can think is there is a hardware problem internal to the Fiber port. 

[Tom Watts]

Hi Indigo, depending what you are interconnecting with, it may be some sort of cross-over issue. I see very often using patch panel, especially LC to SC conversions, the panel can't cross-over correctly.

So, what are you connecting to?

You may also try to loopback the port, putting a tx+tx or rx+rx connection in to the gbic, if the port lights and has the loopback detect, the port is fine, it is a different issue, likely layer 1.

-Tom
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[indigo]

Hi Tom,

I’m trying to get the Port 28 on this SG300-28P switch (Layer 3 mode) to connect to an SG300-20 switch (Layer 2 Mode) on Port 19.

When I unplug the fiber jumper from Port 28, and connect it to Port 27 (which is currently in use for another connection), everything works fine.  I disconnect Port 27, plug it back into Port 28, link lights blink, but no ping.

[Tom Watts]

What modules are you using and what color is the fibre?

-Tom
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[indigo]

We are using the MFEFX1 modules.  What color is the fibre?  What do you mean by that?

[Tom Watts]

orange or yellow? what color is the fibre wire

-Tom
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[indigo]

The jumper cables are orange.  They work fine when attached to an external transceiver, and they work fine when connected to Port 27.

[Tom Watts]

Can you verify the optical module status?

Admin -> Diagnostics -> Optical Module Status

Also, from curiosity can you disable the EEE short reach under the green ethernet settings as well.

Lastly, give the switch a firmware upgrade/flash to the 1.2.7.76 code. Depending on how the module status is looking like, and a software reload, your suspicion may be right, that the port has a damage component.

-Tom
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[indigo]

The status for ports 27 and 28 are the same:  All N/S, then for "Loss of Signal", false.

I've upgraded the firmware to 1.2.7.76, and everything under EEE interface settings for port 28 has been disabled (I'd already tried that before, but I double-checked).

I can't upgrade the other side remotely (since I can't get to it), but I will do that this weekend.

Still no connectivity.  Thanks for responding, it's nice to have someone else to help troubleshoot, I've pulled all that's left of my hair out with this one.

[indigo]

How do I go about RMA'ing this switch?  It's in production, so I can't really pull it to return it without a way to replace it...

[Tom Watts · Accepted solution]

Indigo, you don't have to pull it. The switch is entitled to advance replacement RMA for free. You just need to call the support center, open a ticket, they will go through a troubleshoot process and if the conclusion is the switch is defective, then a switch will be shipped to you, once you receive the replacement, you can return the defective one.

-Tom
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[indigo]

It's not letting me contact support until I've purchased a support contract.  Ugh.

[Tom Watts]

Indigo, the SBSC does not require a contract. Only Cisco TAC does.

Here are the SBSC numbers.

http://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html

If you're having issues reaching through to the SBSC, let me know,I will call you personally.

-Tom
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[KosaAdmin]

Thank you, Tom!  You made my life a whole lot easier.