We will get a /24 public IP address range, and I have to seperate it into few departments.
So my plan is to split the /24 network into several /27 networks.
I wanted to use a Cisco SG300-10SFP to create VLANs with /27 networks.
Do I still need a router in before that SG300 to connect all VLAN gateways with the /24 gateways, or are that SG300 such fancy devices who can manage it?
I never worked with that SG300 so far, a friend suggested them and said they have L3 support.
According to the Cisco 300 Series Managed Switches Data Sheet, the SG300 switches can do IPv4 routing:
You will probably need to configure this on your switch.
You will definitely need a firewall between your switch and the WAN in order to protect your network.
I've seen it previously in an environment which worked fairly well, multiple SG300 switches, routing done at the L3 switch layer of the SG300 and then a Cisco ASA 55xx firewall on the edge of the network facing the redundant ISP connections.
They are not the fastest or most efficient thing out there however some of the functionality that a router would perform can be pushed up to the ASA, the SG300 does have the limitation of not being able to run dynamic routing protocols if I'm not mistaken. Static routing or RIP are the only options in that scenario, can it be done yes...depending on the environment and amount of users. The question comes to mind whenever I hear something like this.... can it be done? Yes, however should it be done?
Do the inter-VLAN routing on the switch because the performance is much better vs a router on a stick topology (where the inter-VLAN routing is done on the router via Ethernet subinterfaces on a trunk).
Well I ended up by using a separate router. Yes the SG300 can do routing, but its a low cost piece of hardware compared with the Catalyst 3750 (where my setup worked fine).
