fiber connection problem

Answered Question
Sep 29th, 2008

Hi Friends

I am trying to connect btween 2 switches on Fiber.

Switch 1 -

Model number: WS-C2924M-XL-EN on GBIC Port Fa 1/3

Switch 2

WS-C2960G-48TC-L on SFP port gig 0/48.

It is not coming up? NO LED at both side.

Need your input please.

regards

Jacob

I have this problem too.
0 votes
Correct Answer by konigl about 8 years 2 months ago

It sounds like Switch 1 is a Catalyst 2924M XL with a 4-port 100Base-FX expansion module (model number WS-X2924-XL-V) installed in one of the modular slots above the 24 built-in 10/100TX ports.

They may look like GBIC ports because they accept patch cables with SC connector ends, just like GBICs do. However, those are Fast Ethernet fiber ports (100FX), not Gigabit Ethernet (1000SX, 1000LX/LH, etc.)

The 100FX ports operate over multimode fiber at a wavelength of 1300nm; and can go up to 412 meters in half-duplex mode, or 2000 meters in full-duplex mode.

If you are trying to connect Switch 1's interface FastEthernet1/3 to a fiber SFP in Switch 2, it will work IF and only if the SFP is one that supports Fast Ethernet (model number GLC-GE-100FX= or GLC-FE-100FX=).

If you are trying to connect it to a Gigabit Ethernet fiber SFP (such as GLC-SX-MM= which operates at a wavelength of 850nm over multimode fiber) it will not work.

If you use a 1-port 1000BASE-X uplink module (model number WS-X2931-XL) you can install a fiber GBIC in it and connect the old Catalyst 2924M XL switch to your new Catalyst 2960G-48TC switch. Just be sure to match the GBIC wavelength (SX, or LX/LH) with the SFP.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4 (2 ratings)
Loading.
rais Mon, 09/29/2008 - 11:30

You can check if the connection is crossed. Try to adjust the speed to 1000Full on switch ports.

Thanks.

Giuseppe Larosa Mon, 09/29/2008 - 11:33

Hello Jacob,

be aware that some old switches have only a fiber based FE uplink (100 Mbps)

so they cannot be used with a GE (1000 Mbps) on the other side no speed negotiation is available on fiber.

I don't think 2924 XL has GE ports we have some in some remote sites or used at access layer.

Hope to help

Giuseppe

Correct Answer
konigl Mon, 09/29/2008 - 12:40

It sounds like Switch 1 is a Catalyst 2924M XL with a 4-port 100Base-FX expansion module (model number WS-X2924-XL-V) installed in one of the modular slots above the 24 built-in 10/100TX ports.

They may look like GBIC ports because they accept patch cables with SC connector ends, just like GBICs do. However, those are Fast Ethernet fiber ports (100FX), not Gigabit Ethernet (1000SX, 1000LX/LH, etc.)

The 100FX ports operate over multimode fiber at a wavelength of 1300nm; and can go up to 412 meters in half-duplex mode, or 2000 meters in full-duplex mode.

If you are trying to connect Switch 1's interface FastEthernet1/3 to a fiber SFP in Switch 2, it will work IF and only if the SFP is one that supports Fast Ethernet (model number GLC-GE-100FX= or GLC-FE-100FX=).

If you are trying to connect it to a Gigabit Ethernet fiber SFP (such as GLC-SX-MM= which operates at a wavelength of 850nm over multimode fiber) it will not work.

If you use a 1-port 1000BASE-X uplink module (model number WS-X2931-XL) you can install a fiber GBIC in it and connect the old Catalyst 2924M XL switch to your new Catalyst 2960G-48TC switch. Just be sure to match the GBIC wavelength (SX, or LX/LH) with the SFP.

minghsiung Mon, 09/29/2008 - 22:55

Hi, if the cable type and interface are alright..maybe you can try swap the TX and RX on the cable pin out..because your case are more likely physical problem if you already done both end with no shut..

hope that help..

Jacob Samuel Tue, 09/30/2008 - 04:57

Dear Friends,

Thanks a lot to all for the valid informaion. especially to Larry, for the details.

The issue is clear now.

If any one can provide some document which will be helpfull for me to convince the customer it will be a great help for me.

Thanks a lot

Regards

Jacob

konigl Tue, 09/30/2008 - 09:00

Data Sheets to help make your case...

Catalyst 2900 Series XL Expansion Modules (documents that the Gigabit Ethernet modules for the 2924M XL switch are different from the Fast Ethernet ones):

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps607/product_data_sheet09186a0080088a16.pdf

Cisco Catalyst 2960 Series Switches with LAN Base Software (documents that the 2960G-48TC switch will support a 100FX SFP, if that's really how the customer wants to connect):

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps6406/product_data_sheet0900aecd80322c0c.pdf

CISCO 100BASE-FX SFP FAST ETHERNET INTERFACE CONVERTER ON GIGABIT SFP PORTS (documents the specific SFP that does 100FX in a Gigabit SFP port on the 2960G-48TC switch, according to the switch's data sheet):

http://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6578/product_data_sheet0900aecd801ba88e.pdf

Wouldn't they rather trade in the 2924M XL under the Cisco Technology Migration Program, or just replace it with a more current and more capable switch? While they can? This one is to be declared End-Of-Life (obsolete) by Cisco on April 9, 2009, according to Product Bulletin No. 2315:

End-of-Sale and End-of-Life Announcement for the Cisco Catalyst 2900 Series XL Modular Switches

http://www.cisco.com/warp/public/cc/pd/si/casi/ca2900xl/prodlit/2315_pp.pdf

Hope this helps.

EDITED TO ADD: What's the distance between the two switches, anyway? And what kind of fiber?

If they are separated by less than 220 meters of multimode fiber, you won't have any problems going to Gigabit Ethernet. If they are between 220 and 550 meters and it's old multimode fiber, a successful link depends on some other factors (quality of the fiber, 62.5/125 versus 50/125, mode-conditioning launch cables, LX/LH transceivers). From 550 to 2,000 meters of multimode, it had better be some recently installed "super" multimode fiber, capable of supporting Gigabit Ethernet operations out to 2km. If it's not, then Fast Ethernet full-duplex is the most you can do with that much multimode.

For anything else you should be using single-mode fiber; and either LX/LH, ZX, CWDM, or DWDM optical transceivers, depending on the distances involved and bandwidth needed.

Jacob Samuel Wed, 10/01/2008 - 03:16

Dear Larry,

Thanks so much for the Links.

We have some swithces WS-C3750-48PS-S for the customer in the new phase of the project to implement. So most probably i will not usethe existing 1900/2900 sereis cisco switches any more.

I will give a new LAN design to the customer. The LAN needs maximum MM fiber only. The small hurdle is, there is no Distribution series switch to aggregate the Fiber uplinks. Most probably i will connect two 3750 as a stack and use as Distribution, so i will get 8 GBIC SFP Ports, it will work.

I would give a very BIG Thanks to Cisco, for the switches 2900/1900, it is working from more than 7 years i think, 24*7 with out much problems or down time.

Thanks again to all for the help

Best regards

Jacob

markfester Tue, 09/30/2008 - 09:32

Jacob,

Fa to Gig? Could be the problem. Fa is 100mb Gig is 1000mb.

Thanks,

Mark

Actions

This Discussion