I need to create several distinct VLANs, and provide a way for traffic to move between them. A "router on a stick" approach seems ideal:
Internet | Router with Trunking Capability ("router on a stick") * * Trunk between router and switch * Switch with Trunking Capability | | | | | | | | | | | LAN 2 | LAN 4 | | 10.0.2.0/24 | 10.0.4.0/24 | | | | LAN 1 LAN 3 LAN 5 10.0.1.0/24 10.0.3.0/24 10.0.5.0/24
We have trunk-capable Layer-2 switches. The question is what to use as the router on a stick. My choices seem to be:
- Use an existing Cisco 5505 ASA firewall. It appears the ASA can do the routing, but it's a 100Mbps device, and so seems sub-optimal at best
- Buy a router. This seems overkill.
- Buy a Layer-3 switch. Also seems overkill.
- Use an existing, shared Linux Box as a router (e.g. the NIS server)
- Use a dedicated Linux box as a router
- Something I'm not thinking of
I think either (4) or (5) is my best option, but I'm not sure how to choose between them. I expect the amount of traffic that has to cross the VLANs to be somewhat small, but bursty. How much load does routing add to a CentOS machine?