Q. Do the Cisco Catalyst 3750 Series Switches interoperate with SFPs from other vendors?
A. Yes, starting from 12.2(25)SE release, the user has the option via CLI to turn on the support for 3rd party SFPs. However, the Cisco TAC will not support such 3rd party SFPs. In the event of any link error involving such 3rd party SFPs the customer will have to replace 3rd party SFPs with Cisco SFPs before any troubleshooting can be done by TAC
Many companies are seeking for Cisco SFP alternatives to help cut down the costs on these expensive modules. A frequent customer problem with Cisco's new line of Catalyst switches is that they do not support 3rd party (non-Cisco) SFPs - or at least they do not seem to... If you've just replaced your network switches and tried using any 3rd party SFPs to connect your network backbone, you'll quickly stumble across an error similar to the following:
%PHY-4-UNSUPPORTED_TRANSCEIVER: Unsupported transceiver found in Gi1/0/0
%GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port 65538 has bad crc
The Catalyst switch has just disabled the GBIC port! This happens because Cisco Catalyst switches are configured by default not to work with non-Cisco SFPs.
When a SFP is inserted into a switch's GBIC port, the switch immediately reads a number of values from the SFP and if it doesn't like what it sees, it throws the above error message and disables the port.
All SFP modules contain a number of recorded values in their EEPROM and include:
- Vendor Name
- Vendor ID
- Serial Number
- Security Code
- CRC
There are two undocumented commands which can be used to force the Cisco Catalyst switch to enable the GBIC port and use the 3rd party SFP:
3750G-Stack(config)# service unsupported-transceiver
Warning: When Cisco determines that a fault or defect can be traced to
the use of third-party transceivers installed by a customer or reseller,
then, at Cisco's discretion, Cisco may withhold support under warranty or
a Cisco support program. In the course of providing support for a Cisco
networking product Cisco may require that the end user install Cisco
transceivers if Cisco determines that removing third-party parts will
assist Cisco in diagnosing the cause of a support issue.
3750G-Stack(config)# no errdisable detect cause gbic-invalid
When entering the service unsupported-transceiver command, the switch will automatically throw a warning message as a last hope to prevent the usage of a 3rd party SFP.
The no errdisable detect cause gbic-invalid command will help ensure the GBIC port is not disabled when inserting an invalid GIBC.
Since the service unsupported-transceiver is undocumented, if you try searching for the command with the usual method (?), you won't find it.
The same applies for the no errdisable detect cause gbic-invalid command.
We tried both service unsupported-transceiver & no errdisable detect cause gbic-invalid commands on 2960G, 3560G, 3750G, 4507R and 4507R-E Catalyst switches and all accepted the commands without a problem. In fact if the Catalyst switch is running IOS 12.2(25)SE and above, the undocumented commands are available.
Source: Firewall .cx, Routing Information & Expertise To Networking Professionals
URL: http://www.firewall.cx/cisco-technical-knowledgebase/cisco-switches/866-cisco-switches-3rd-party-sfp.html
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