[c-nsp] nexus 5548 versus C4900M

[Holemans Wim]

We have a service cluster build around a C4900M : it concentrates a mix of 10G (intercampus) connections and 1G connections (some backup lines and central services such as DNS, VPN servers,...)
This works fine but to be able to connect all these, I had to add the 20 port 10/100/1000 UTP card and the extra 8x 10G card (with X2 convertor to provide for fiber SFPs). At the time that seemed a good and reasonable priced solution. This C4900M only does L2 traffic for the moment but will do some minor static (500Mb) IPv4 L3 routing in the near future.

Now I have to create a new, similar  service cluster. The first idea was to copy the setup but as we are also looking at Nexus for our datacenter, I noticed the Nexus 5548UP. This gives you out-of-the-box 32 1G/10G ports and costs (based on the prices I have seen) 25% less than the above C4900M configuration.
Anyone has a reason why we should stick to the C4900M (or maybe similar C4500 solution) and not put a Nexus in place, apart from the obvious differences between IOS and NXOS for management ?
I think, when adding the L3 card to the Nexus, the 25% price difference will disappear but are there any limits you see (arp table, mac address table size, buffering, IPv6 support..) that would take the Nexus out of the picture ?

Greetings,

Wim Holemans
Netwerkdienst Universiteit Antwerpen
Network Services University of Antwerp