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.
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.
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
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:
no ip address
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
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!
You can check the compatibility documents to find out which pluggable optics modules are supported on your platform.
It does not list any 10Gbps pluggable optics options for the 3945 router.