Cannot get link on Cisco 3650 with Gigabit Copper SFP's

Posted on 2006-04-18
Last Modified: 2012-08-14
We are using copprt SFP's, they *should* be 10/100/1000. No matter what we try to connect to one of these four SFP ports, we do not get link. I have tried mutliple devices, each with multiple cables and multiple speed and duplex settings, and the port stays in a "notconnect" state.

Our goal is to use this switch as the core, and uplink four cheap Dell PowerConnect switches to these Gigabit ports.

Cisco 3650, running 12.2(25).

and yes, we shut/no shu the port every time we re-attempt/reconnect

We also recieve max CPU errors when we plug in the SFP's when the switch is online, if we REMOVE an SFP while the switch is humming along, the switch crashes.

Thanks in advance,

pdx-3560# sh port interface GIgabitEthernet 0/1
Port Security              : Disabled
Port Status                : Secure-down
Violation Mode             : Shutdown
Aging Time                 : 0 mins
Aging Type                 : Absolute
SecureStatic Address Aging : Disabled
Maximum MAC Addresses      : 1
Total MAC Addresses        : 0
Configured MAC Addresses   : 0
Sticky MAC Addresses       : 0
Last Source Address:Vlan   : 0000.0000.0000:0
Security Violation Count   : 0

GigabitEthernet0/1 is down, line protocol is down (notconnect)
  Hardware is Gigabit Ethernet, address is 0016.c898.5e81 (bia 0016.c898.5e81)
  Description: Dell Switch 1
  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
  Full-duplex, 1000Mb/s, link type is auto, media type is 10/100/1000BaseTX SFP
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  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 multicast)
     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
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 3 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
Question by:shaaad
    LVL 11

    Expert Comment

    I had a similar issue.  What is that switchport mode set to on that SFP Gig port?  If not already, set to:

    switchport mode dynamic desirable

    Otherwise, are there any other customizations you have done?

    Author Comment

    No luck. No, nothing else custom on the switch or port, but have tried many different configs.  I'm thinking it's hardware at this point, I'm not sure
    how i can further troubleshoot this hunch.
    LVL 11

    Accepted Solution

    Buy another ;-)  

    I assume from your original posting that you tried that SFP in a different GB port to rule out a physical port problem?  The only reason why I initially had a problem was because of the mode access setting on the 3560 and also the port setting on the switch that I was linking up to.  Once I matched those to dynamic, I got my link lights.  Sorry I can't be of more help, but good luck!

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    Highfive + Dolby Voice = No More Audio Complaints!

    Poor audio quality is one of the top reasons people don’t use video conferencing. Get the crispest, clearest audio powered by Dolby Voice in every meeting. Highfive and Dolby Voice deliver the best video conferencing and audio experience for every meeting and every room.

    What’s a web proxy server? A proxy server is a server that goes between clients and web servers, used in corporate to enforce corporate browsing policy and ensure security. Proxy servers are commonly used in three modes. A)    Forward proxy …
    Data center, now-a-days, is referred as the home of all the advanced technologies. In-fact, most of the businesses are now establishing their entire organizational structure around the IT capabilities.
    Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.
    Here's a very brief overview of the methods PRTG Network Monitor ( offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

    779 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    9 Experts available now in Live!

    Get 1:1 Help Now