[c-nsp] LX GBIC at half duplex?

Rich Davies rich.davies at gmail.com
Tue Oct 23 15:03:13 EDT 2012


If you have an fiber coupler (SC) you can loop TX to RX and verify that
link comes up on the 3550 side on your section of fiber.   Also if media
converter has ability to do any internal loop tests (in either direction)
that would be good too.    You may be able to plug an ethernet RJ45
loopback into the media converter and in turn loop it thru media converter
and across the fiber.

Based on what you told me it sounds like media converter is bad....  but
try any looping you can with the circuit to determine where its failing.
 You should be able to at least verify if your GBIC and fiber is good.


Rich


On Tue, Oct 23, 2012 at 2:40 PM, Jason Lixfeld <jason at lixfeld.ca> wrote:

> Hi all,
>
> Running up against an odd issue where we have a 3550 with an LX GBIC
> trying to talk to a copper port on an ME3600 with a media converter in the
> middle.  The ME3600 side always shows as up; we disabled fault passthrough
> on the MC.  The LX GBIC on the 3550 side shows down/down with negotiation
> enabled, so with negotiation disabled, it shows up/up, but at half
> duplex(?!).  Anyone seen this before?  I didn't think an LX GBIC at half
> duplex was possible, even with negotiation disabled as there is still no
> way to force the duplex in that state.  Bad GBIC?  Media converter borked?
>  Gremlins?
>
> I'd be grateful for any insight gleaned from prior experiences..
>
> Thanks in advance.
>
> For completeness:
>
> Model number: WS-C3550-24-SMI
> System image file is "flash:c3550-ipservicesk9-mz.122-35.SE5.bin"
>
> TOYF-1.10-1.A920#show int g0/1
> GigabitEthernet0/1 is up, line protocol is up (connected)
>   Hardware is Gigabit Ethernet, address is 0014.6aa4.0c00 (bia
> 0014.6aa4.0c00)
>   Description: Facing gi0-24.pe01.171EastLibertySt01.YYZ
>   Internet address is 1.1.1.1/30
>   MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
>      reliability 255/255, txload 1/255, rxload 1/255
>   Encapsulation ARPA, loopback not set
>   Keepalive not set
>   Half-duplex, 1000Mb/s, link type is force-up, media type is 1000BaseLX
>   input flow-control is off, output flow-control is on
>   ARP type: ARPA, ARP Timeout 04:00:00
>   Last input 23:14:46, output 00:00:02, output hang never
>   Last clearing of "show interface" counters 06:02:06
>   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, 144492 bytes, 0 no buffer
>      Received 0 broadcasts (0 IP 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
>      326 packets output, 122306 bytes, 0 underruns
>      0 output errors, 0 collisions, 0 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
> TOYF-1.10-1.A920#sh run int g0/1
> Building configuration...
>
> Current configuration : 167 bytes
> !
> interface GigabitEthernet0/1
>  no switchport
>  ip address 1.1.1.1 255.255.255.252
>  speed nonegotiate
> end
>
> TOYF-1.10-1.A920#show mac address-table int g0/1
>           Mac Address Table
> -------------------------------------------
>
> Vlan    Mac Address       Type        Ports
> ----    -----------       --------    -----
> TOYF-1.10-1.A920#
>
> .........
>
>
> TOYF-1.10-1.A920#sh int g0/1
> GigabitEthernet0/1 is down, line protocol is down (notconnect)
>   Hardware is Gigabit Ethernet, address is 0014.6aa4.0c00 (bia
> 0014.6aa4.0c00)
>   Description: Facing gi0-24.pe01.171EastLibertySt01.YYZ
>   Internet address is 1.1.1.1/30
>   MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
>      reliability 255/255, txload 1/255, rxload 1/255
>   Encapsulation ARPA, loopback not set
>   Keepalive not set
>   Auto-duplex, Auto-speed, link type is auto, media type is 1000BaseLX
>   input flow-control is off, output flow-control is on
>   ARP type: ARPA, ARP Timeout 04:00:00
>   Last input 23:18:01, output 00:00:18, output hang never
>   Last clearing of "show interface" counters 00:00:32
>   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 IP 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
>      4 packets output, 1210 bytes, 0 underruns
>      0 output errors, 0 collisions, 0 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
> TOYF-1.10-1.A920#sh run int g0/1
> Building configuration...
>
> Current configuration : 148 bytes
> !
> interface GigabitEthernet0/1
>  description Facing gi0-24.pe01.171EastLibertySt01.YYZ
>  no switchport
>  ip address 1.1.1.1 255.255.255.252
> end
>
> TOYF-1.10-1.A920#
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