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Abelchala's avatar
Abelchala
Aspirant
Dec 19, 2017

M4100 Fiber port not working when connected with another switch fiber port (GS278TPP)

Dears,

I have one M4100-12GF Netgear Switch, with 12 combo ports (fiber and ethernet). 

The M4100 is used to aggregare other switches, which actually connect my IP Cameras. VLAN 20 is configured as Camera VLAN, and have assigned PoE ports for the same. 

 However, the challenge I am facing now is that I am not able to connect the M4100 via fiber port (for example, port 11 F at the M4100 with fiber port 25 on GS728TP Switch ).  

I did specify port 11F, and port 25 as trunk, and have configured both ports as trunk. 

 When I connect two ports using a multimode fiber cable (which is 50/125 OM3 Multimode), the port on the M4100 Switch does not give light. 

 Please assist.

5 Replies

  • Hi Abelchala,

     

    There can be a few reasons for the fibre connection not working. I have listed 3 common ones below.

     

    1. How far are your switches apart and what type of fibre are you using (multi-mode or single-mode)? Multi-mode is used for short distances and is the "cheaper" form of fibre modules. Typically, the max distance for multi-mode is 500m (but that can vary). Single-mode modules are more expensive, but have much greater greater range. Often 10-20 KMs. You need to make sure that you use Single-mode fibre modules if your switches are far apart and you must make sure that you use the same type of module (single/multi-mode) in each end.

     

    2. Have you checked the fibre polarity? You need to make sure that transmit in one end, goes to receive in the other end - and vice versa. Else it won't work. This is important! Try to swap the transmit with receive, in one end.
    Like this: http://community.fs.com/blog/wp-content/uploads/2016/06/polarity.jpg

     

    3. Even though fibre is a standard, sometimes certain modules won't work with certain switches. It is just hardware compatibility. This is why Netgear lists official compatible modules in the datasheet, for each switch. That being said, it often will work with different vendor modules, but not always!

     

    These Netgear modules should work with your switches:
    NETGEAR AGM731F (multi-mode)
    NETGEAR AGM732F (single-mode)

     


    Cheers

    • Abelchala's avatar
      Abelchala
      Aspirant

      Hi Hopchen,


      Thank you for the kind response. 

       

      Regarding your questions, we are testing the switch integration from data center, and the distance between two switches will not exceed 500 meters. 

       

      The fiber cable we are using is Multimode which is in comliance with the datasheet  (both M4100-12GF , and GS728TPP switches). 

       

      The fiber polarity, we checked and seems to be fine. But we are also going to try the single mode now. 

       

      Just one question sir/madam - we connected two fiber ports (one at GS728TP, and one at M4100-12GF), the port at the GS Switch is amber, but the M4100 port is not showing any activity - the light is not on.  What could be the cause ? 

       

      • Hopchen's avatar
        Hopchen
        Prodigy

        Hi again,

         

        The amber light on ports is normally an indication that the port is not running at it's full speed. For example, a 1Gbit/s port running at 100Mbit/s. However, I don't think that is the problem here. The amber light is more likely an indication there is a problem with the connection. Especially because the other switch has no lights on the port. The amber in this case is probably because there is connectivity in one direction, but not both directions.

         

        - What fibre modules are you using?


        - Please try and change the fibre cable as well. Perhaps it's a bad cable.


        - Remember that the M4100-12GF switch is using RJ45 and Fibre as combo ports. This means that for any port, you can either the RJ45 or the fibre. Not both at the same time! You are using port 11. Please ensure that 11T has nothing plugged into, if you intend to use 11F for the fibre connection.

         


        Thanks

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