09-27-2010 10:04 PM
My provider (Deutsche Telekom) is only able to hand over a 1Gbps-Link with speed und full-duplex configured fix.
To force the router (cisco 3945) for 1000/full, I had to remove the 'media-type sfp'
SFP is MM-SX on Router-Interface Gi0/2
This configuration worked a while but shows many interface resets (more than 30 in one minute).
Telekom confirmed, their connection is working properly.
After switching the router off an on, I could no longer connect with telnet or ssh. Ping is also not successful but cdp shows the neighbor router!?!
Maybe this is a problem with SFP and duplex configuration.
Any ideas?
09-28-2010 04:24 AM
Hello,
with Gigabit there is only full. But it could also be the software. A customer of us has had almost the same problems and by a software update the problem was repaired.
02-26-2016 01:28 AM
my problem is that my cisco router 3845-MB has its interface gig0/0 down. admistratively down. the ios version is the 12.4(20)T4 ,do i upgrade the version? if yes which one doesnt have a such bug.
thanks to reply
09-28-2010 07:48 AM
have you tried the command speed nonegotiate under the interface?
09-28-2010 08:06 AM
*speed nonegotiate* is not available to configure
09-28-2010 09:14 AM
Software-Update to 151-2.T1 did not solve the issue, either :-(
09-28-2010 03:20 PM
A GLC-SX-MM will always negotiate to full 1G.
09-29-2010 08:05 AM
After replacing the 3945 with a 3845 the Link is up and running - without any 'interface resets'
11-25-2010 12:47 PM
Hi, I'm facing a similar issue with a 3845 with GLC-SX-MM module trying to connect at 100Mbps with a telco device. Documentations says 'media-type sfp' defaults to 1Gig, and only changing to 'media-type rj45' would allow me to set 100Mbps instead. Any clue what should I do in order to allow speed compatibility with this telco device ? Follows the current interface config:
Interface GigabitEthernet0/0
description ---
bandwidth 100000
no ip address
duplex auto
speed 1000
media-type sfp
negotiation auto
11-25-2010 11:35 PM
Hi,
with IOS version 15.0(1)M4 the Gig interface can be left on speed/duplex autosensing mode. Its default is to connect with 1000/full, again.
IOS versions before connected with half-duplex.
The new software fixed the Bug CSCtj35792
11-25-2010 11:36 PM
the command 'no negotiation auto' should fix your issue
on a 3845
11-26-2010 07:48 AM
In order to connect to a 100BaseFX link, you will need to install a GLC-GE-100FX SFP module in your 3945 switch. This 100M SFP module is designed to be installed in a GE SFP slot.
If, in the future, you want to support GE on the 3945 switch's port, you will have to change the SFP to a compatible GE module.
Hope this helps!
Tom
11-30-2010 02:45 AM
the request was to connect a 1000/full link.
After the software update it works without any problems
09-24-2011 03:41 AM
Did Router 3945 SFP Port support SFP-10G-LR, How to define it ?
09-24-2011 06:43 AM
You can check the compatibility documents to find out which pluggable optics modules are supported on your platform.
http://www.cisco.com/en/US/products/hw/modules/ps5455/products_device_support_tables_list.html
It does not list any 10Gbps pluggable optics options for the 3945 router.
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