When you insert the TwinGig Converter in a Catalyst 4900M you get the following error message:
%C4K_TRANSCEIVERMAN-3-SEEPROMREADFAILED: Failed to read transceiver serial eeprom on port Te2/1, try reinserting
This error is probably because the device expects 10Gig transceivers to be connected to the device not 1Gig.
To use the TwinGig module you need to use the following command and change to Gig Ethernet:
"hw-module module <slot> port-group <group> select gigabitethernet"
Here is the sequence:
1. Insert the module and it will give the following error.
%C4K_TRANSCEIVERMAN-3-SEEPROMREADFAILED: Failed to read transceiver serial eeprom on port Te2/1, try reinserting
2. Add “hw-module module 2 port-group 1 select gigabitethernet” command
*Apr 15 03:07:56: %C4K_GLMMAN-3-X2INTWINGIGCONVERTERHOLE: X2 inserted in port Te2/2, which is configured for a TwinGigConverter
4w4d: Port Te2/1: TwinGig Converter inserted: vendor: CISCO SYSTEMS, p/n: 800-27645-01, s/n: FDO12140G92
So it will detect the TwinGig module.
3. Insert GLC-T in left side of TwinGig and it will detect the GLC-T as Gi2/9 port.
Also keep in mind on these TwinGig converters in the 4900M, the next 2 ports in that hardware group can only be gigabit, you cannot make the next port in the hardware group 10 gig once you have selected gigabit as the speed for that hardware group, so if ports 1 and 2 are gigabit then ports 3 and 4 can only be gigabit. This is a hardware limitation.