Hi,
I need a switch that can support legacy 1Gbps uplinks to the backbone, 1Gbps to servers (over fibre and copper) and has the scalability of providing 10Gbps to servers to meet future growth.
Short of opting for a fully modular chassis, the next best thing seems to be the 4900M switch. However I find its lack of supporting the TwinGig modules on the chassis ports rather annoying. This means I have to sacrifice one of the 20-Port 10/100/1000BaseTX modules, and use the 8-Port X2 10 GigabitEthernet module with TwinGig converters instead.
If my understanding is correct, in order to provide non blocking uplinks to my backbone (dual homed) over 1Gbps SFP I need to use one port only in two of the port groups (to ensure full forwarding line rate. I can then use the other port groups and install GLC-T SFPs to try and bump up the copper port densities.
Not an altogether "elegant" method, but it seems Cisco have limited the flexibility of this switch by limiting where the TwinGig modules can work - very annoying.
Anyway, here is my config straight from the configuration tool.
WS-C4900M
Base system with 8 X2 ports and 2 half slots 1
S49MESK9-12246SG
Cisco CAT4900M IOS ENTERPRISE SERVICES SSH 1
WS-X4920-GB-RJ45
20 port 10/100/1000 RJ45 1
WS-X4908-10GE
8 port 2:1 10 GE card 1
GLC-T
1000BASE-T SFP 4
GLC-T
1000BASE-T SFP 4
GLC-SX-MM
GE SFP, LC connector SX transceiver 2
GLC-LH-SM
GE SFP, LC connector LX/LH transceiver 2
PWR-C49M-1000AC
4900M AC power supply, 1000 watts 1
PWR-C49M-1000AC/2
Redundant AC PS for 4900M 1
CAB-CEE77-C15-EU
CEE 7/7 to IEC-C15 8ft Europe 2
Included: CVR-X2-SFP
Cisco TwinGig Converter Module 2
Included: CVR-X2-SFP
Cisco TwinGig Converter Module 2
Included: CVR-X2-SFP
Cisco TwinGig Converter Module 2
Included: CVR-X2-SFP
Cisco TwinGig Converter Module 2
Included: 4900M-X2-CVR
X2 cover on 4900M 8
