12-08-2014 07:51 AM - edited 03-07-2019 09:48 PM
I have set up Cisco switches previously via the hyperterminal and been able to get them configured and operating, but I have limited knowledge of the tools and processes.
I have a 2960-S with 48 ports and 4 SFP modules.
I have good feedback on the 48 ports, but I can not get the SFP modules to ether be recognized or show any activity on the 2960-S. The unmanaged switch I have the fiber connected too, is indicating a network connection and activity, but the 2960-S is not indicating any connection on the SFP modules.
I have added the switch configuration file.
12-08-2014 01:26 PM
Post the photo of the SFP.
Post the output to the command "sh version".
12-09-2014 09:35 AM
12-09-2014 09:49 AM
12-08-2014 03:07 PM
When dealing with add on SFP's, you can type "show inventory" to see if they are recognized by the system at all. It will also show the model and serial number, as well as linecards, power supplies, etc.
I've run into some issues with 3rd party SFP's before, and they typically won't come up if they are not recognized as a Cisco branded version. If you issue a "show interface" on the interface you are having problems with, and the status is errdisabled, it may be because you have used an SFP that isn't recognized.
There is a hidden command you can use, "service unsupported-transceiver" which, in conjunction with "no errdisable detect cause gbic-invalid" and "errdisable recovery cause gbic-invalid", allows you to use the SFP. I will note that you should use Cisco branded SFP's whenever possible, as off branded ones are most of the time less reliable and don't enable the full options that Cisco branded ones would.
12-09-2014 09:41 AM
12-09-2014 04:45 PM
Ok. I see you posted your config above, and after reading a bit more here, you're dealing with layers 1-2 of the OSI model at the moment, so let's focus on that. For your unmanaged switch, are you using the same type of SFP? Sometimes you need to use the same on both sides for a link to come up. I have tried off branded + Cisco before and it had lots of problems. Also
If that is not the problem, I would say look over your running-configuration for port 49. It does not appear to have any configuration added to it so far. If every device on your unmanaged switch will be on the same vlan, you can turn port 49 into 'switchport mode access' and 'switchport access vlan 1' as well as 'spanning-tree portfast'.
If not all devices will be on vlan 1 on your unmanaged device, you can try 'switchport mode trunk'. This will allow vlans 1-4094 across by default (you can limit this too). Make sure that the unmanaged switch is set to trunk mode as well, and allowing the vlans you want across.
For troubleshooting, you can try 'show spanning-tree vlan <xxx>' where xxx is the vlan you are having trouble with. Lastly, you can also try to issue a 'show interface gig 1/0/49 counters detail', which will show you all the types of packets entering the port. This varies from ios version to ios version, but it will show unicast, multicast, broadcast, packets below the MTU or above (runts and giants).
I hope that helps : )
01-24-2015 02:40 AM
Hi Patrick
01-24-2015 05:19 AM
I have already responded to your THREAD.
01-24-2015 08:50 AM
Hi,
I've not run into this situation and honestly couldn't answer without making a guess. Leo replied to your post and sent a link to various SFP's that may work. Good luck!
12-09-2014 06:00 AM
Hello,
check your IOS in the 2960:
- c2960x-universalk9-mz.150-2.EX4 has a bug with SFP.
- you can use instead c2960x-universalk9-mz.150-2.EX3
Then, you can issue the following commands:
- sh int status --> show state of all interfaces
- sh controllers ethernet-controller int-type/int-number ph det --> shows all details connected SFP
- sh int int-type/int-number transceiver detail --> check if you have light in your end.
Level of (-40dBm) means no signal in there. Even with signal, the SFP can be disconnected or not passing traffic. But first of all is to have light on your end.
Regards,
Reg.
12-10-2014 12:21 AM
I forgot to tell:
try to issue the "speed nonegotiate" and disable it again on the interface port level.
Regards,
Reg.
08-24-2017 08:18 AM
I have a 2960-S switch attached via GLC-SX-MM Multimode Fiber connect to a SG300-10MP switch. The SG is essentially unmannaged at this point, so telling the port on the 2960-S to not negotiate the speed was exactly the thing that allowed this connection to work. There were other times it worked, but it took random amounts of time for this to occur (Never right away like it should). I'm assuiming because both ends were negotiating the entire time, neither came up with an agreement? IDK, but this fixed it. Thank you very much!
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