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Can CEF720 24 port 1000mb SFP support SX as well as LX

A Chairde,

I am trying to connect a GBE SX Device to my 7609 , but am getting line protocol+interface down, I have GBE LX devices already connected+working, do you know if my board supports it, and if so, how to configure.


24 CEF720 24 port 1000mb SFP WS-X6724-SFP


cnibhco100#SH VER

Cisco Internetwork Operating System Software

IOS (tm) s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M), Version 12.2(18)S


Technical Support:

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

Compiled Mon 20-Jun-05 21:37 by kellythw

Image text-base: 0x40021040, data-base: 0x42B08000

ROM: System Bootstrap, Version 12.2(17r)S2, RELEASE SOFTWARE (fc1)

BOOTLDR: s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M), Version 12.2(18)S


cnibhco100 uptime is 4 weeks, 5 days, 4 hours, 41 minutes

Time since cnibhco100 switched to active is 4 weeks, 5 days, 4 hours, 40 minutes

System returned to ROM by unknown reload cause - suspect boot_data[BOOT_COUNT] 0

x0, BOOT_COUNT 0, BOOTDATA 19 (SP by power-on)

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cisco CISCO7609 (R7000) processor (revision 1.1) with 983008K/65536K bytes of me


Processor board ID FOX084101ET

SR71000 CPU at 600Mhz, Implementation 0x504, Rev 1.2, 512KB L2 Cache

Last reset from s/w peripheral

SuperLAT software (copyright 1990 by Meridian Technology Corp).

X.25 software, Version 3.0.0.

Bridging software.

TN3270 Emulation software.

1 Enhanced FlexWAN controller (1 POS).

1 Virtual Ethernet/IEEE 802.3 interface

74 Gigabit Ethernet/IEEE 802.3 interfaces

1 Packet over SONET network interface

1917K bytes of non-volatile configuration memory.

8192K bytes of packet buffer memory.

65536K bytes of Flash internal SIMM (Sector size 512K).

Configuration register is 0x2102



Re: Can CEF720 24 port 1000mb SFP support SX as well as LX


I feel your trying to interface SX port and LX port thatis SX on ur new equipment side and LX on ur 7609 side, if this is rite i would suggest to change the LX module to SX on your 7609 and give a try.

We do have LX and SX modules installed on the same WS-X6724 board but with the other end/side having the same kinda modules installed in them..


New Member

Re: Can CEF720 24 port 1000mb SFP support SX as well as LX

Apologies for the confusion,

I have SX Connections on my WS-X6724 , they are working as the other side is GBE SX.

My problem is I have now connected New GBE LX Boards in equipment on other side , but when I connect Fibre cable into WS-X6724 , and do a SH IP INT GI 1/7

I get that Interface/Line protocol are down.

Was wondering if this was because I needed to add configuration to my port, my board , as it does not seem to have picked up the LX Port automatically.

I am using same cabling to LX as for SX, maybe this is the problem ??

Re: Can CEF720 24 port 1000mb SFP support SX as well as LX


AFAIK LX belongs to single mode type and SX of multimode type.

you need to have multimode fiber patchcords when ur connecting SX to SX and u can have single mode fiber for connection LX to LX.

So i dont feel connecting this LX and SX will work out for you.

BTW using which cable you are interfacing these modules ? is it a sinlge mode or multi mode ?

As i suggest in my earlier post do check out using LX and LX on both the sides.


New Member

Re: Can CEF720 24 port 1000mb SFP support SX as well as LX

Connecting LX-LX is not possible.

It must be SX-SX , I will probably have to get a module for WS-X6724 board to support SX and get single mode cables.

Re: Can CEF720 24 port 1000mb SFP support SX as well as LX


You cannot connect LX to SX modules, this will not work. You need same type of boards at both the ends. From your post , believe you have SX at one end and LX at other and this will not work.

I had the same problem a few days back, my 6513 went down one me with WS-X6724. I tried connecting the uplink on Sup ports and they were using LX SFP while the other side was on SX. I changed the SX SFC on my SUP and got the connection back.


-amit singh

New Member

Re: Can CEF720 24 port 1000mb SFP support SX as well as LX


If you change the GBICs from LX to SX, and from multi-mode to single-mode , it should work.

Slan / Ed

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