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Connectivity issue when using Gigabit ethernet module


I have a smaller network spanning 3 buildings, only needing 1 3650 Catalyst POE switch in each building. Switch 1 and 2 are connected by a fiber connection, and switch 2 and 3 are connected by an Aeronet 1400 wireless shot.

I have 4 servers, and wanted to get them all on a Gigabit 'backbone'. My switches are all 10/100, so I bought two cisco GLC-T modules - they are Small Form Factor modules that plug into the little expansion bays on the end of the switch, thereby allowing that one port to become Gigabit ethernet.

However, I have no network connectivity when plugged into these modules, even though though the port light is green. When I telnet into the port, and do a 'show gigabitethernet 0/2' the results clearly show that there is a 1000 base T module plugged into it. I cannot access or ping anything, either when plugged directly into the module, or when plugged into a Linksys Gigabit switch, in turn plugged into the module. I have this problem with either module, on any of the three switches.

I am gratefuel for any advice you can provide.


Re: Connectivity issue when using Gigabit ethernet module

Can you post the show version of the 3560 where you plug in the GLC-T modules? Have you tried disabling the speed negotiation with "speed nonegotiate" under the interface with GLC-T?


Re: Connectivity issue when using Gigabit ethernet module

Hello Malberttoo,

To verify if your configuration is valid use:

show version - to verify that your software code is the recommended version, as stated on the compatability chart.

show interface Gi0/2 - look at interface statistics, is the line and link status "up"?

show idprom interface Gi0/2 - verify if the transceiver is recognized by the switch


New Member

Re: Connectivity issue when using Gigabit ethernet module

Bosalaza, here are the results of my Show Version:

Cisco IOS Software, C3560 Software (C3560-IPSERVICES-M), Version 12.2(25)SEB1, R


Copyright (c) 1986-2005 by Cisco Systems, Inc.

Compiled Fri 29-Apr-05 22:25 by yenanh

ROM: Bootstrap program is C3560 boot loader

BOOTLDR: C3560 Boot Loader (C3560-HBOOT-M) Version 12.2(25r)SEA, RELEASE SOFTWAR

E (fc)

CommRoomSwitch uptime is 6 weeks, 6 days, 4 minutes

System returned to ROM by power-on

System restarted at 19:04:02 UTC Sat Apr 29 2006

System image file is "flash:c3560-ipservices-mz.122-25.SEB1/c3560-ipservices-mz.


cisco WS-C3560-24PS (PowerPC405) processor (revision M0) with 118784K/12280K byt

es of memory.

Processor board ID CAT0923R1BA

Last reset from power-on

2 Virtual Ethernet interfaces

24 FastEthernet interfaces

2 Gigabit Ethernet interfaces

The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory.

Base ethernet MAC Address : 00:14:6A:6E:0C:80

Motherboard assembly number : 73-9673-06

Power supply part number : 341-0029-03

Motherboard serial number : CAT092303KJ

Power supply serial number : DTH09206X52

Model revision number : M0

Motherboard revision number : A0

Model number : WS-C3560-24PS-E

System serial number : CAT0923R1BA

Top Assembly Part Number : 800-26380-03

Top Assembly Revision Number : A0

Version ID : V05

CLEI Code Number : COM1100ARB

Hardware Board Revision Number : 0x01

Switch Ports Model SW Version SW Image

------ ----- ----- ---------- ----------

* 1 26 WS-C3560-24PS 12.2(25)SEB1 C3560-IPSERVICES-M

Configuration register is 0xF

I know next to nothing about configuring these switches, so I have not adjusted any settings. Should I add the command to the interface, as you have described?

Leon, the Show Interface is indeed up:

GigabitEthernet0/2 is up, line protocol is up (connected)

Hardware is Gigabit Ethernet, address is 0014.6a6e.0c82 (bia 0014.6a6e.0c82)

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 00:02:49, output 00:00:00, 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 2000 bits/sec, 3 packets/sec

1296 packets input, 114704 bytes, 0 no buffer

Received 1143 broadcasts (0 multicast)

0 runts, 0 giants, 0 throttles

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

0 watchdog, 568 multicast, 0 pause input

0 input packets with dribble condition detected

57266 packets output, 4389801 bytes, 0 underruns

0 output errors, 0 collisions, 1 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

And here is the Show IDProm:

General SFP Information


Identifier : 0x03

Connector : 0x00

Transceiver : 0x00 0x00 0x00 0x08 0x00 0x00 0x00 0x00

Encoding : 0x01

BR_Nominal : 0x0D

Vendor Name : Methode Elec.

Vendor Part Number : SP7041

Vendor Revision : 0x41 0x20 0x20 0x20

Vendor Serial Number : M820389

Thank you both very kindly for your replies!


Re: Connectivity issue when using Gigabit ethernet module

Try it. the interface is up/up but do not see input, how are you verifying that it's not passing traffic? Waht is the other end of this interface? Can you try assigning a vlan that is not used anywhere else on this port or making it a layer 3 port. the point of the suggestion is to use ping test to see if it's passing traffic. show interface does not show me ip address so it must be a switchport. what does show int gig 0/2 counter show? any unicast rx, mcat rx or broadcast rx?

New Member

Re: Connectivity issue when using Gigabit ethernet module

The "nonegotiate" part of the command is unsupported on this device, it appears.

I'm verifying the lack of connectivity in no technical way, just the fact that any device plugged into one of these ports does not get a DHCP address from my server, and has no internet or network access.

Show interface...counter yields the following:

Port InOctets InUcastPkts InMcastPkts InBcastPkts

Gi0/2 99272 0 18 821

Port OutOctets OutUcastPkts OutMcastPkts OutBcastPkts

Gi0/2 239219 5 3111 0

Here is the part where my ignorance really shows, but I don't know how to put the port on an unused Vlan, or even create another Vlan for that matter.

Thanks again for your advice.


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