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speed/duplex issue

Anukalp S
Level 1
Level 1

Hi.. I have 1921 router in which i have inserted fiber SFP in a slot. Strange behaviour i am observing is that even after configuring speed/duplex auto on this interface, it still showing speed1000 & duplex full. But when i do sh int <int name> i see duplex/auto auto negotiable.

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

interface GigabitEthernet0/0/0
 duplex full
 speed 1000
end

Command-NJ-AVPN#
Command-NJ-AVPN#sh int g0/0/0
GigabitEthernet0/0/0 is down, line protocol is down
  Hardware is EHWIC-1GE-SFP-CU, address is d072.dc31.7548 (bia d072.dc31.7548)
  Auto Duplex, Auto Speed, media type is unknown media type
  output flow-control is XON, input flow-control is XON

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

Pls help, if this is expected behaviour or there is some issue.

14 Replies 14

Walter Astori
Level 1
Level 1

Can you add under GigabitEthernet0/0/0 the command media-type SFP

yes.after setting media-type SFP i dont see config of speed/duplex. But if i want to  set speed/duplex in media type SFP mode why i dont find option. When i put media-type RJ 45 i get option to change duplex/speed. Am i not be able to change speed/duplex in media-type SFP mode.

 

router(config)#int g0/0/0

router(config-if)#media-type sfp
GigabitEthernet0/0/0: Changing media to SFP.
You may need to update the speed and duplex settings for this interface.
router(config-if)#
router(config-if)#speed
router(config-if)#speed 10000
                            ^
% Invalid input detected at '^' marker.

router(config-if)#spee
router(config-if)#speed 100
                            ^
% Invalid input detected at '^' marker.

router(config-if)#

After that you execute the command media-type SFP, can you execute "show interface GigabitEthernet0/0/0/" command ?

 

Hi. Pls see below.

 

router#sh int g0/0/0

GigabitEthernet0/0/0 is down, line protocol is down

  Hardware is EHWIC-1GE-SFP-CU, address is d072.dc31.7548 (bia d072.dc31.7548)

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

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

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Auto Duplex, Auto Speed, media type is LX

  output flow-control is XON, input flow-control is XON

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

  Last input never, output never, output hang never

if the line protocol is down and GigabitEthernet0/0/0 is down then you must verify if the cable is plug in to the media type

 

Hi Walter..you mean to say after pluging cable into port, i will be able to change speed/duplex on interface having media-type sfp configured.

HI,

Have you tried the command under the interface Media type Sfp.

and after that you will be change the Speed

Inter 

Media Type sfp 

speed 

This will work

Regards,

Gurudath K S

It could be a bug.  With SFP, you shouldn't be able to configure speed and duplex.  

Thanks Laohoo.. You sound correct, is there any fix for this bug.

Try a different IOS version and see if you see the same behaviour.  

Anukalp

You may have to configure duplex first. Please check if you are able to configure duplex, Also what is the IOS version you are using?

 

 

 

Raj..its not working.

router(config)#int g0/0/0
router(config-if)#dupl
router(config-if)#duplex full
                            ^
% Invalid input detected at '^' marker.

router(config-if)#duplex ?
% Unrecognized command

 

Cisco IOS Software, C1900 Software (C1900-UNIVERSALK9-M), Version 15.2(4)M6, REL
EASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2014 by Cisco Systems, Inc.
Compiled Wed 19-Mar-14 11:56 by prod_rel_team

ROM: System Bootstrap, Version 15.0(1r)M16, RELEASE SOFTWARE (fc1)

Command-NJ-AVPN uptime is 2 hours, 2 minutes
System returned to ROM by power-on
System image file is "usbflash0:c1900-universalk9-mz.SPA.152-4.M6.bin"
Last reload type: Normal Reload
Last reload reason: power-on

devils_advocate
Level 7
Level 7

I could be wrong but my understanding is that a Gigabit SFP port can only run at 1000 Full so the fact it says Auto matters none because the port will simply be 1000 Full or nothing.

If you went into Interface Configuration mode, you likely won't even be able to set the Speed and/or Duplex because the port is 1000 Full or nothing.

If I look at one of our 1GB SFP Ports it shows Auto so I believe this is normal:

GigabitEthernet0/9 is down, line protocol is down (notconnect)
  Hardware is Gigabit Ethernet, address is ccd5.39dc.4389 (bia ccd5.39dc.4389)
  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 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 Not Present
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00

 

Hi devils..

Your understanding looks correct, seraching for document related this.

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