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New 2960 Switch Can't Connect to Media Converters

Ed Willson
Level 1
Level 1

I just installed a new 2960 to replace a 3550 this last weekend.  All of the fiber media converters will not connect to the new switch.  The converters are made by Black Box and Desa.  If I plug them into the 3550 they link up immediately.  If I plug them into the 2960 there is no link whatsoever.  Any ideas?  I've tried letting it auto-negotiate and tried turning off inline power on the 2960 with no luck.

2960:

FastEthernet0/5 is down, line protocol is down (notconnect)

  Hardware is Fast Ethernet, address is 0022.91f6.aa05 (bia 0022.91f6.aa05)

  Description: Mazak

  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Half-duplex, 10Mb/s, media type is 10/100BaseTX

  input flow-control is off, output flow-control is unsupported

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input never, output 00:38:25, output hang never

  Last clearing of "show interface" counters 01:39:39

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

  Queueing strategy: fifo

  Output queue: 0/40 (size/max)

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 0 bits/sec, 0 packets/sec

     0 packets input, 0 bytes, 0 no buffer

     Received 0 broadcasts (0 multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 0 multicast, 0 pause input

     0 input packets with dribble condition detected

     31448 packets output, 3530944 bytes, 0 underruns

     0 output errors, 0 collisions, 2 interface resets

     0 babbles, 0 late collision, 0 deferred

     0 lost carrier, 0 no carrier, 0 PAUSE output

     0 output buffer failures, 0 output buffers swapped out

3550:

FastEthernet0/40 is up, line protocol is up

  Hardware is Fast Ethernet, address is 0009.4347.cea8 (bia 0009.4347.cea8)

  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,

     reliability 255/255, txload 2/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive not set

  Half-duplex, 10Mb/s, 100BaseTX/FX

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input never, output 00:00:01, output hang never

  Last clearing of "show interface" counters never

  Queueing strategy: fifo

  Output queue 0/40, 0 drops; input queue 0/75, 0 drops

  5 minute input rate 16000 bits/sec, 8 packets/sec

  5 minute output rate 94000 bits/sec, 20 packets/sec

     14856 packets input, 2567842 bytes

     Received 163 broadcasts, 0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 13 multicast

     0 input packets with dribble condition detected

     36506 packets output, 21669837 bytes, 0 underruns

     0 output errors, 4339 collisions, 3 interface resets

     0 babbles, 0 late collision, 121 deferred

     0 lost carrier, 0 no carrier

     0 output buffer failures, 0 output buffers swapped out

Thanks,

   Ed

1 Accepted Solution

Accepted Solutions

Thanks for the update Ed.

I am inclined to believe it was speed/duplex mismatch somewhere in the chain.  But ultimately glad you got it working, and I am sure you are too! Woohoo!!

View solution in original post

23 Replies 23

jimmysands73_2
Level 5
Level 5

Some of the basics:

You verified the port(s) on the 2960 work when a diff known working device is plugged in?

Are there any jiumpers that you can set the speed/duplex on the converters (or have you hard set them on the switch)?


Your 2960 is not showing any inputs, so from the switch perspective its not seeing any traffice.

Some media convertes will take the sw port down (notconnect) if their fiber uplink is disconnected (of better said, if not layer one link exist on the fiber site), others I have seen will let the sw port stay up, even w/no fiber link.  I have not worked with the ones you mentioned unfortunately (we use Milan, Raven, RCM, Point Systems).

      

Odd issue your having.

I haven't touched the media converters - They are 10/100 or 10, it's amixed bag.  I just configured the switchports the same.  I know the Black Box has something like Auto-MDIX, and so does the 2960.  The 3550 doesn't have Auto-MDIX ports.  I did verify that the port is working on the 2960 as well.  The really strange thing is that it is happening to multiple media converters from multiple brands. 

Thanks,

   Ed

Again, maybe the obvious, have you tried rolling the fiber?  But then again, if the tx/rx have not been touched, then you shouldnt have too.  I was just thinking maybe the sw port is down due to the fiber being down, but that doesnt apply here.  Some key piece is missing from this issue....have you tried various speed/duplex settings on the 2960?  Maybe the media converters are set via jumpers (hard set) and since the 3550 might also be hard set, where the 2960 is trying to let it auto negotiate.  But if your using multiple ones from diff vendors, probably all not hard set.  Again, just a hypothesis.

Can you check that the switch interface's speed and duplex are set to "AUTO"?

Why use a media converter in the first place?  Stick the appropriate SFP module in.

I've tried setting the speed/duplex to auto with no luck.  I'd be happy to use an SFP, are there 10BaseT available? 

Thanks,

    Ed

I've tried setting the speed/duplex to auto with no luck.  I'd be happy to use an SFP, are there 10BaseT available?

No 10 Mbps fibre optic modules but there are 100 Mbps ones.

10 Mbps fibre????  Is this from the ISP?

We have serval machines that are connected directly with fiber.  All very old and very expensive.  The fiber terminates inside the machines with propriatary adapters. The EM radiation eliminates copper as an option..

Thanks,

   Ed

Nuts.  I hate to be in your shoes now.

My cohort said the same thing

Sent from Cisco Technical Support iPhone App

glen.grant
VIP Alumni
VIP Alumni

  Try turning auto mdix off (no mdix auto) .  If it is on  and any ports are hardcoded then the interfAce will not come active. 

I did try "no mdix auto" on the switchport.  Same thing:

FWS-Hen-Swi-5#sh controll eth fa0/5 phy | i MD

Auto-MDIX                             :  Off   [AdminState=1   Flags=0x00013148]

000F: 0051 DTE Power Via MDI (DPM)               :  0000 0000 0101 0001

I also flip flopped the MDI/MDIX switch on the media converter...

Thanks,

   Ed

Ed,

To clarify, the only thing swapped out was the switch?  This is strange.  The MDI/MDIX I believe is used to toggle the media converter if its expecting to see a crossover or straighthrough cable.  My only guess is that media converters are hard set with speed/duplex and the 2960 is set to auto. How very odd.

Good luck!  Please update when you find resolution, quite interested.

Hey Jimmy,

The only thing I can think of right now is to run a TDR.  What do you think?

Can anybody please clarify this TDR term a bit or provide a link.. i could not clear it from google.

--

Parvesh

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