C7000, Cisco 3120 subnets

[Terry Brent]

I am replacing a system of several servers with an HP C7000 blade system. The C7000 has BL460s with 6 nics, 6 cisco 3120gs nw switches, 2 cisco 9124E fibre switches, HP EVA 4400 san and VMWare enterprise. The switches are to be redundant pairs. The existing system was physically separated into two domains with 3 subnets each then star networked thru dumb switches to workstations / printers. I'm told I must add a core switch, replace all dumb switches and add a router to get 4 - 10 subnets out of the C7000. Is that correct ? If not, can you point me in the right direction ?

[Lmm_1]

It sounds right, if you have different VLANs on the 3120 you will need a router to have communication between those VLAN´s, you should have same VLANs on your core, otherwise it will end up being the same broadcost domain.

Another option will be update 3120 IOS with a version capable of L3, then you can do your routing on your switches, it will not alleviate the upstream switch issue.

[Steven Clementi]

The 3120's should be fullable configurable Cisco switches and allow for up to 4095 vlans.

The is only limited by your existing network infrastructure. If you have several "dumb" switches connecting all of your other gear, then they don;t know how to pass vlan traffic across a trunk connection. They are incapable of this and therefore pass ALL traffic across connections with other switches.


Your best bet is to talk with your vendor/reseller to see if they have any technical resources that specialize in this type of hardware. At the very least, you can call HP to get installation services or even a different 3rd party (another reseller WITH resources OR a company that does just services).


Steven

[Terry Brent]

First, thanks for taking the time to consider this setup.

Our existing network is wired completely separate by subnet.

I'm wanting the 3120's configured so 6 to 8 of the external ports can each be their own subnet. So, plugged into port 1 is subnet #1, port 2 is subnet #2, port 3 is subnet #3, up thru 6 to 8 subnets. Thus our existing gear would only see the one subnet they're connected to.

Let me know if I need to clarify any of this.